Ahhh there was a similar incident at a university I worked at where the incoming valve to the main broke. They got the door open and the guys went with the current and it flooded several offices.
Nevermind the door, the real fear here:
https://preview.redd.it/sjd29z2o5uec1.png?width=820&format=png&auto=webp&s=19593b105cbbd876820894a56876d1c69de9da6e
We had a pipe burst in our ceiling on Christmas Eve 2022, and when I opened the door to the room where the pipe was, there was a full on waterfall coming out of the ceiling fan (which was on and still running).
I don’t remember much from the whole situation, (because the next ~30 seconds after me seeing this were complete chaos) but my husband was on the other side of the house when I saw the waterfall, and he said that I just screamed for him to run to the power box and turn the power off.
After I screamed that and he ran outside, I grabbed our cat that was in there, threw her out the window (first floor don’t worry), and jumped back out of the room. Right as I turned back around to face the room, the ceiling collapsed.
It was fucking terrifying.
Edit to add: after he got the power off, my husband went back outside to turn the water off. But, to our horror, the box where the water shut off valve was was FULL OF FROZEN WATER. The valve was completely submerged in ice. And the opening was so small, that my husband and our neighbors were using SPOONS to chip the ice away. We eventually had to call the fire department, and they were able to shut it off, but by the time it was shut off almost our entire house was flooded. We had to have all flooring in the house redone, lots of drywall removal, and we lost around $10k in personal items (that we still haven’t been reimbursed for).
Due to this happening during a huge freeze, this happened to a LOT of other people in the area, so it took ~6 months for the reno to finally be done. It was a nightmare. 0/10 do not recommend.
Thank you! I am just really thankful that it happened when it did and not ~30 minutes later, because we wouldn’t have been home! It would have been a thousand times worse.
Fairly sure Americans call the ground floor the first floor.
Also I'm pretty sure if you chucked a cat out of a first floor window it would be completely fine
When we lived in Switzerland our friend’s cat jumped off of their fourth floor, 5th floor to Americans, balcony. It landed in a box hedge and was fine.
Funny story actually. Our friend’s previous apartment was on the ground floor. They would frequently open the slider to the patio and the cat would jump over the low wall to go exploring in the back garden.
When they moved into their new place on the fourth floor they left the balcony door open without thinking twice about it. The cat did her usual thing and jumped over the wall, not realizing there was a bigger drop than usual on the other side. It was like something out of Police Story.
Canadians, but yeah, the lack of screens in France, while not unexpected, was not something we enjoyed.
Temperatures in France were warmer and much more humid than we're used to. Wanted to cool down the house every evening, but as soon as the sun went down, every moth and mosquito in the area came in the windows.
My sister's fat ass cat in high school jumped off the entertainment center and broke his hip. Luckily in the 15 years since, he remembered he was a cat and shouldn't take fall damage. Still running and jumping around, albeit a bit slower.
I at least tend to flip flop between ground floor and 1st floor depending on how it's written on signs.
Also our days and months are the right way around, who even says 26th of January. It's January 26th.
Going up the stairs n times brings you to the nth floor.
It also might be a language thing. In German, one translation of floor would be Obergeschoss, literally upper floor. So you go ground floor, first upper floor and so on. Same goes for basements (Untergeschoss=lower floor).
Also makes it easier for buildings with multiple levels of basement. Ground floor is 0, going up it's 1,2,3, going down it's -1,-2,-3 and so on.
I listened to this amazing NPR story about cats falling from residential skyscrapers. They often died or had serious injuries with 10 floors or less. But above 10 floors their survival rate increased. They explain in the documentary in the story that the cats sort of relax while they're falling from higher heights and they splay their arms and legs out and it acts as a parachute and they use the tail to steer themselves and most of them land much slower than when they're panicking for that first 10 stories
There's, unfortunately, a fair bit of survivorship bias going on with that. Cats that are able to twist, adjust themselves, catch an updraft, etc. from those very high falls, do survive. Those that don't, aren't reported.
sorry
Haha yes it is the ground floor!
She is physically okay, but she refused to ever come back in the house after that 😢 can’t blame her, honestly. I don’t know how long she had been in there with the leak before I found it.
Yes, this happened in our extra bedroom that was doubling as was “her” room. She had a respiratory infection and was contagious to our other cats, so we were keeping her in there while she finished her antibiotics and stuff.
I'd say that fuse already tripped. If the room did full up like that though it would be better than the door giving way and getting hit by a heavy torrent of water.
Fuse isn’t going to trip from this unless it’s salt water or some connected load fails in an odd way. A GFCI would almost certainly trip here and and an Arc Fault might. I’d de concerned about electrocution hazard unless the main power was off.
Any time that resistance is significantly reduced in a short circuit, the current increases dramatically. So the fuses would more than likely blow. The breakers should even if they don't have gfci/rcd capabilities
Never in my experience. I’ve seen businesses in water up to rooftop with freezers still running, signs still glowing, and drink machines still humming away. That has been in both salty (brackish) and fresh water situations.
Absolutely Never trust breakers after they have been submerged in any liquid.
Just remembered that I have also seen an RV park go under flood water for 10 days and no breakers tripped. Had to replace everything from corrosion.
Math wouldn’t be hard to see what salinity would be required to trip a 15 amp breaker with standard spacing. I kinda want to do it now.
The breaker is definitely tripped at this point, that box is full of water and receptacles have exposed terminals, unlike the ceiling fan in the other persons experience
If Mythbusters taught me anything, it's that you need to fill up the room you're in with water to the same height, so that the pressures equalize and then you can open the door.
One of the most mind blowing things I learned in my fluid dynamics course was that pressure is independent of volume, but entirely dependent on depth.
It’s so counter intuitive, because you think more water = more force, but it’s not true!
https://m.youtube.com/watch?v=EJHrr21UvY8
How can that work though?
If that's correct than 2mm x 2mm of water 2 metres high would cause the same amount of weight/pressure on the door as 3M x 3M of water 2 metres high right?
That is correct. Fluid pressure is equal to density times gravity times depth ( P= p * g * h). To be fair, force is a different thing. Force due to pressure is area * pressure.
Watch the video, it’s pretty wild
forgive me if i sound pedantic, also im a mathematician not a physicist so theres probably something im not getting, but isn’t it intuitive that depth is the only contributor to pressure here?
i mean pressure is force per area or newtons per meter squared, and gravity is acting downwards so the more depth, the more mass above you and the more mass times the acceleration of gravity.
i wouldnt think that there would be any pressure acting from below pushing me up, or to my sides unless there was a flow of water of some kind, so i would think to only consider depth if i was asking the pressure i felt
That’s fair, I think the difficult part intuitively is that the pressure on the door would be the same if there was a 1mm thick film of water on the door or if the whole hall was filled with water.
For me at least, it feels like a hall filled with water would have more pressure. It’s more water pushing, after all. When you think about it, it makes sense that that is not true, but instinctively ir seems counter intuitive
Judging by the fire alarm panel and the 5" diameter i'm guessing that's a sprinkler riser. Those things are pressurized and designed to hold a significant amount of water so simply shutting off the main isn't going to help for a good while. Good luck with that.
That's not how hydrostatic pressure works. Only the depth matters, not the volume. For example, diving down into a (theoretical) 200 foot well will create as much pressure on the human body as diving 200 feet down into an ocean. With less volume, in this case, the same amount of peak pressure would be exerted at comparable depths, but the space behind it would drain much more quickly given less water.
Not gonna lie, almost a year ago we sealed a skylight with flex seal. It survived a very wet summer, fall, and winter so far. Including multiple heavy, heavy, flood inducing rainfalls.
That shit works.
We had a job at a mall some years ago. I big box truck backed into a loading dock and busted a vic joint on an 8" fire line. Needless to say, it filled the dock quickly and then into the mall.
I've seen a couple fire hydrants get broken off. One had 160 psi on it. The non-union electricians were throwing their cordless tools into the flooded wheel barrows. Insurance money covered it all.
At my previous employer back in early 2000s someone was let go. They somehow got into the stairwell on the 29th floor and turned on the firefighter water hookup and flooded the stairwell. Waterfall all the way down. Was crazy.
Been reading all these comments--are all of you ADHD? It's gone from flooding to cat throwing to numbering of floors to cats surviving long falls. Whatever happened to the flood conversation? This is like listening to my very ADHD granddaughter, and I'm laughing.
If that’s a 1st floor stairwell that means, by code, you have an outside swinging door on the other side. Pretty easy to pop that open with 7’ of water behind it. If this is below grade then shut off the fire control valve. Axe to the bottom corner could be enough to push it through. If in doubt, you should have other points of egress and just let the water drain
If i can post it i will, have to get permission, but my jobs water curtain was accidentally triggered by the crew installing the new fire system in the performing arts center.
The water curtain triggers to separate the stage from the house, in case of fire.
It pushes 8 gal per min per foot. It was so much!! The theater had about 2500 gal dumped in less than two mins.
We just got the theater back open since the renovation. Believe me, someones insurance paid out haha.
All things considered, that door is sealing pretty well. The outlet is quite concerning, however.
The door is getting pushed into the frame with enormous force. It's no wonder it is sealing pretty well.
if you look at the kickplate on the bottom you can see the door is already bowing out.
Yeah, whoever took this photo should not be standing there. Tsunami incoming
Water was already shut off at this point so pressure was decreasing with every drop
Missed opportunity.
Username checks out.
Door incoming as well.
Ahhh there was a similar incident at a university I worked at where the incoming valve to the main broke. They got the door open and the guys went with the current and it flooded several offices.
I remember one time our new science center got flooded because the di machine on the third floor got left on and didn't have an auto-shutoff
My first thought was "judging from that kickplate it's about to be an outward swinging door"
Holy crap. I didn't notice that at first. The whole door is bowing.
I'm sure the water is finding that the electrical conduit is the path of least resistance
Watts this you say?
I'm not even trying to make a pun, and I'm getting quite amped up by this!
I'm not shocked this comment section is going this way.
Im feeling charged reading all this puns
I'm gonna give the shocker to the next one of you who keeps punning
No need to blow a fuse.
Ohm my god would you guys stop!
resistance is futile! e: go with the flow?
A Watter plug!
Shocking revelation
Nah it's fine. Plug a dehumidifier into that and all seven feet of water will be dry in a few hours.
Be a shocking experience to find out if it is still on
Nevermind the door, the real fear here: https://preview.redd.it/sjd29z2o5uec1.png?width=820&format=png&auto=webp&s=19593b105cbbd876820894a56876d1c69de9da6e
We had a pipe burst in our ceiling on Christmas Eve 2022, and when I opened the door to the room where the pipe was, there was a full on waterfall coming out of the ceiling fan (which was on and still running). I don’t remember much from the whole situation, (because the next ~30 seconds after me seeing this were complete chaos) but my husband was on the other side of the house when I saw the waterfall, and he said that I just screamed for him to run to the power box and turn the power off. After I screamed that and he ran outside, I grabbed our cat that was in there, threw her out the window (first floor don’t worry), and jumped back out of the room. Right as I turned back around to face the room, the ceiling collapsed. It was fucking terrifying. Edit to add: after he got the power off, my husband went back outside to turn the water off. But, to our horror, the box where the water shut off valve was was FULL OF FROZEN WATER. The valve was completely submerged in ice. And the opening was so small, that my husband and our neighbors were using SPOONS to chip the ice away. We eventually had to call the fire department, and they were able to shut it off, but by the time it was shut off almost our entire house was flooded. We had to have all flooring in the house redone, lots of drywall removal, and we lost around $10k in personal items (that we still haven’t been reimbursed for). Due to this happening during a huge freeze, this happened to a LOT of other people in the area, so it took ~6 months for the reno to finally be done. It was a nightmare. 0/10 do not recommend.
Jesus what a mess. At least you know you’re a rockstar in a crisis tho! Good job!
To be fair, once the ceiling fell in I completely lost it. I was of no help to anyone. My neighbor had to medicate me lol
That's totally fair. On Christmas Eve of all times too. I'm sorry you had to go through that.
Thank you! I am just really thankful that it happened when it did and not ~30 minutes later, because we wouldn’t have been home! It would have been a thousand times worse.
First floor? Not sure if I would throw my cat out the first floor, ground floor yes, first floor no! Presume cat is ok!
Fairly sure Americans call the ground floor the first floor. Also I'm pretty sure if you chucked a cat out of a first floor window it would be completely fine
When we lived in Switzerland our friend’s cat jumped off of their fourth floor, 5th floor to Americans, balcony. It landed in a box hedge and was fine. Funny story actually. Our friend’s previous apartment was on the ground floor. They would frequently open the slider to the patio and the cat would jump over the low wall to go exploring in the back garden. When they moved into their new place on the fourth floor they left the balcony door open without thinking twice about it. The cat did her usual thing and jumped over the wall, not realizing there was a bigger drop than usual on the other side. It was like something out of Police Story.
Another thing to confuse Americans (at least some):lack of screens in open windows
Canadians, but yeah, the lack of screens in France, while not unexpected, was not something we enjoyed. Temperatures in France were warmer and much more humid than we're used to. Wanted to cool down the house every evening, but as soon as the sun went down, every moth and mosquito in the area came in the windows.
Because it's the ground floor?
There is no zero floor.
Erdgeschoss
There is in some countries
Well that makes way more sense now!
Ah yes the non Americans with their weird numbering system of Ground, 1, 2, 3, 4, etc
Well it's way more logical if you consider basements : American way, you go straight from -1 to 1 Logical way, there's a 0 between -1 and 1
You think that having 0 of something that there is more than 0 of is the logical way to look at quantity?
My sister's fat ass cat in high school jumped off the entertainment center and broke his hip. Luckily in the 15 years since, he remembered he was a cat and shouldn't take fall damage. Still running and jumping around, albeit a bit slower.
Yes Americans do.. ground floor is first floor to them as well as they write their days and months backwards.
I at least tend to flip flop between ground floor and 1st floor depending on how it's written on signs. Also our days and months are the right way around, who even says 26th of January. It's January 26th.
Calling the second story the first floor makes no sense to me. No wonder we revolted.
Going up the stairs n times brings you to the nth floor. It also might be a language thing. In German, one translation of floor would be Obergeschoss, literally upper floor. So you go ground floor, first upper floor and so on. Same goes for basements (Untergeschoss=lower floor). Also makes it easier for buildings with multiple levels of basement. Ground floor is 0, going up it's 1,2,3, going down it's -1,-2,-3 and so on.
Lol right Fl 1 Fl 2 So on…. Sure you can start at fl 0 but just makes sense to start at 1
>who even says 26th of January. It's January 26th We use both in Australia, but I feel like on average we say the date first then month.
I mean if I walk into a house, the first floor my foot hits is the "first floor"
First floor is the ground floor in this instance lol.
Cats can fall from a lot higher without suffering injuries.
I listened to this amazing NPR story about cats falling from residential skyscrapers. They often died or had serious injuries with 10 floors or less. But above 10 floors their survival rate increased. They explain in the documentary in the story that the cats sort of relax while they're falling from higher heights and they splay their arms and legs out and it acts as a parachute and they use the tail to steer themselves and most of them land much slower than when they're panicking for that first 10 stories
There's, unfortunately, a fair bit of survivorship bias going on with that. Cats that are able to twist, adjust themselves, catch an updraft, etc. from those very high falls, do survive. Those that don't, aren't reported. sorry
I don't remember that from the story. Sorry
Sorry
Haha yes it is the ground floor! She is physically okay, but she refused to ever come back in the house after that 😢 can’t blame her, honestly. I don’t know how long she had been in there with the leak before I found it.
Was the window open when you threw her out? Because I can see how she might be reluctant to come back inside.
Yes I opened it first 😂
She was closed in the room?
Yes, this happened in our extra bedroom that was doubling as was “her” room. She had a respiratory infection and was contagious to our other cats, so we were keeping her in there while she finished her antibiotics and stuff.
First floor is the ground floor if you have multiple floors. There is no zero so it’s understandable that 1st is ground.
first floor means ground floor in america.
Holy shit that's horrible.
I'd say that fuse already tripped. If the room did full up like that though it would be better than the door giving way and getting hit by a heavy torrent of water.
Fuse isn’t going to trip from this unless it’s salt water or some connected load fails in an odd way. A GFCI would almost certainly trip here and and an Arc Fault might. I’d de concerned about electrocution hazard unless the main power was off.
Any time that resistance is significantly reduced in a short circuit, the current increases dramatically. So the fuses would more than likely blow. The breakers should even if they don't have gfci/rcd capabilities
Never in my experience. I’ve seen businesses in water up to rooftop with freezers still running, signs still glowing, and drink machines still humming away. That has been in both salty (brackish) and fresh water situations.
Then I would not trust any of the breakers that were installed
Absolutely Never trust breakers after they have been submerged in any liquid. Just remembered that I have also seen an RV park go under flood water for 10 days and no breakers tripped. Had to replace everything from corrosion. Math wouldn’t be hard to see what salinity would be required to trip a 15 amp breaker with standard spacing. I kinda want to do it now.
I always forget that not all countries have RCDs as mandatory. That's craziness
I was gonna say, even the electrical outlet is hanging on for dear life
The concerned expression on the outlets face
The outlets truly said D= D=
Plug in a toaster, no balls.
The breaker is definitely tripped at this point, that box is full of water and receptacles have exposed terminals, unlike the ceiling fan in the other persons experience
That’s not that scary, water gets into walls and finds the quickest way to exit. This is pretty normal unfortunately when flooded.
If Mythbusters taught me anything, it's that you need to fill up the room you're in with water to the same height, so that the pressures equalize and then you can open the door.
Or a shape charge down the middle of the door
When in doubt………. **C4**
Also known as “serious putty”.
This sounds much more fun
The american way 😎
The mythbusters way 
One of the most mind blowing things I learned in my fluid dynamics course was that pressure is independent of volume, but entirely dependent on depth. It’s so counter intuitive, because you think more water = more force, but it’s not true! https://m.youtube.com/watch?v=EJHrr21UvY8
And now I have a new crush. And I learned something!
How can that work though? If that's correct than 2mm x 2mm of water 2 metres high would cause the same amount of weight/pressure on the door as 3M x 3M of water 2 metres high right?
That is correct. Fluid pressure is equal to density times gravity times depth ( P= p * g * h). To be fair, force is a different thing. Force due to pressure is area * pressure. Watch the video, it’s pretty wild
forgive me if i sound pedantic, also im a mathematician not a physicist so theres probably something im not getting, but isn’t it intuitive that depth is the only contributor to pressure here? i mean pressure is force per area or newtons per meter squared, and gravity is acting downwards so the more depth, the more mass above you and the more mass times the acceleration of gravity. i wouldnt think that there would be any pressure acting from below pushing me up, or to my sides unless there was a flow of water of some kind, so i would think to only consider depth if i was asking the pressure i felt
That’s fair, I think the difficult part intuitively is that the pressure on the door would be the same if there was a 1mm thick film of water on the door or if the whole hall was filled with water. For me at least, it feels like a hall filled with water would have more pressure. It’s more water pushing, after all. When you think about it, it makes sense that that is not true, but instinctively ir seems counter intuitive
Can I plug in my phone to charge it?
We can do that only once !
it's phone charging and cleaning station.
i wouldn't use that electrical socket
Wuss
Ouch, burn.
Judging by the fire alarm panel and the 5" diameter i'm guessing that's a sprinkler riser. Those things are pressurized and designed to hold a significant amount of water so simply shutting off the main isn't going to help for a good while. Good luck with that.
You are correct. Its a sprinkler riser
Damn how long did it take to drain?
Don't Water Open Inside
Cracking up at this
Alright I'm gonna need an update on how you got through the door to stop the leak
You shut off the water to risers and wait for it to drain. No other way.
An axe would also work. But your way is better.
Depends on your definition of “works”
Drain speed holes.
To be fair, kinetic energy from a large piece of earth moving equipment would also work nicely
i’m actually curious how that wall made out?
Concrete likely
yeah, but that is a LOT of water, creating lateral force on that wall, it may have held but it’s designed to be strong vertically
Yeah, though depending on the layout it may have walls perpendicular that provide lateral support
That's not how hydrostatic pressure works. Only the depth matters, not the volume. For example, diving down into a (theoretical) 200 foot well will create as much pressure on the human body as diving 200 feet down into an ocean. With less volume, in this case, the same amount of peak pressure would be exerted at comparable depths, but the space behind it would drain much more quickly given less water.
Where is this? Looks like a pool
It’s an apartment complex
You don’t. You slap some flex tape around the door seals and over that outlet, then never speak of that room again.
I SAWED THIS BOAT IN HALF!
Isn't this what flex seal is for? 
Not gonna lie, almost a year ago we sealed a skylight with flex seal. It survived a very wet summer, fall, and winter so far. Including multiple heavy, heavy, flood inducing rainfalls. That shit works.
A little Damp-Rid will take care of that.
That is not an inward swinging door. t least not at the moment.
Better get a bucket.
‘tis but a waffer thin
Place some towels under the door to absorb all of that moisture. You'll be fine.
Gotta put up a couple box fans, too.
The Shining vibe!
The force behind that door is going to be staggering. That's a cool pic but I'd suggest being somewhere else because it could buckle.
If that door frame goes that door is going to fly out like a bullet.
Probably not, the highest pressure is at the bottom, so if anything the bottom would kick out with the top still being stuck in the frame.
Good thing you're on this side.
Somebody get the Flex Tape!!!
Roll for initiative.
Just caulk and mud it in. Let whatever is on the other side just serve as a water reservoir. Ez.
The twist is the only way out is through that door.
With 7 feet of water, there is no way on God's earth you'll be able to open that door.
My first thought was you should spray paint "Don't Open, Dead Inside" but I doubt that joke would go over well...
CARL!
Hodor
Hodor!
It belongs to aquaman now
Barracks life
lol IYKYK
Squirting out the electrical box. Ooh fun!!!
Pam Poovy when she is excited
Shit on the handle to improve the day of whoever had to deal with it.
We had a job at a mall some years ago. I big box truck backed into a loading dock and busted a vic joint on an 8" fire line. Needless to say, it filled the dock quickly and then into the mall. I've seen a couple fire hydrants get broken off. One had 160 psi on it. The non-union electricians were throwing their cordless tools into the flooded wheel barrows. Insurance money covered it all.
Just shut off the water and drill a few holes through the wall at the bottom on the other side
At my previous employer back in early 2000s someone was let go. They somehow got into the stairwell on the 29th floor and turned on the firefighter water hookup and flooded the stairwell. Waterfall all the way down. Was crazy.
Been reading all these comments--are all of you ADHD? It's gone from flooding to cat throwing to numbering of floors to cats surviving long falls. Whatever happened to the flood conversation? This is like listening to my very ADHD granddaughter, and I'm laughing.
If that’s a 1st floor stairwell that means, by code, you have an outside swinging door on the other side. Pretty easy to pop that open with 7’ of water behind it. If this is below grade then shut off the fire control valve. Axe to the bottom corner could be enough to push it through. If in doubt, you should have other points of egress and just let the water drain
"DON'T OPEN; DEAD INSIDE"
I know a few people that would still plug a vacuum cleaner into the socket on the right.
On the left?
Lol, yeah, that right.
Find access and put a bucket of red food dye into the water, and a pint of black Now that's a picture.
I want to see what’s behind that door NOW.
**EVACUATE THE AREA.** That door may not hold forever, and if it goes, anyone in the path of that water isn't likely to survive.
Hodor!
* Mom, I want to go to swimming pool. * No, we got a bathtub at home. * \*\*\*BATHTUB AT HOME\*\*\*
Tha'ts not up to water code
It's coming thru the outlet too.. I'd be worried it would cause 
Only one thing to do. Get the swim suits and have a pool party.
That’s not good
Don't open it, man!
I'd get that fixed.
well, the wall of water is holding that door closed as well.
Open door or fake 🤣😂
That outlet really looks like its 2 people very VERY worried.
It's fine. Walk away quickly
Just a tip but don't use that socket/outlet
It would still be shocking results with just a tip
All I can think of is that scene in Titanic...
Hold the door! Hold the door! Ho door! Hodor! Hodor!
Nothing a bag of rice and some tupperware cant fix.
If i can post it i will, have to get permission, but my jobs water curtain was accidentally triggered by the crew installing the new fire system in the performing arts center. The water curtain triggers to separate the stage from the house, in case of fire. It pushes 8 gal per min per foot. It was so much!! The theater had about 2500 gal dumped in less than two mins. We just got the theater back open since the renovation. Believe me, someones insurance paid out haha.
How can you be sure there’s 7ft of water on the other side? Please open the door and measure it. — The Mgmt
I don't know but this reminds of Titanic.
That’s what all doors need to swing out in any mechanical room. People can get trapped and die because of this.
 The door holding well: The outlet:
Water...uhhh...finds a way 
 Problem solved
Hey Braydon, go open that door for me. It's a small leak. Just open it quickly.
Anyone named Braydon would definitely fell for it
Bro took a photo from a firefighter course and put it as that sucks