Id on't mind being near a dead body, got over that as a teen candystriper. We had to take stuff to the morgue from labor and delivery and the ER all the time. They supposedly tried not to have bodies in there when we took stuff down, but for a couple of us who had been there a long time (average length of time was about 3 months) they gave up on that. So I saw lots of dead bodies. Plus one of my bro's friends in elem school lived in a mortuary so when I was there they often tried to lock me into the viewing rooms or the embalming room. At 5 and 7 it was scary, not so much after that. (THen my pedicatrician bought the place and moved the practice into it - talk about wierd!)
I think ANYTHING left in a pool more than a day is a problem - at least safety wise. The fact that it was a dead body and was under the surface and no kid went down and looked just seems odd. At our pool there are always some kids diving for coins or dive sticks or something. And they have their eyes open.
I think she wasn't seen because the pool was cloudy - to me that is a huge safety issue. How would they know a kid was in trouble or kids were holding each other down below the surface? Also how would they know if a little kid pooped in the pool? It happens a couple of times a summer here and they have to filter all of the water, treat it with heavy duty chemicals, and filter it all again before they can open. Often they lose the day it happened and the next day's business and they make the parents of the child pay for it, about $300. If it is a small child and they have a swim diaper (sold for $2 at the pool or BYO) then they don't get the fees or the closing. If it is a child alone or with an underage babysitter the parents have to pay. They had one summer where it happened a lot because parents were using the pool as free daycare - drop off the kid with some snack money and pick them up after work. But the kids caused big problems, and some of the boys found it hilarious to take a dump in the pool - three were banned for life because they were actually pulling their pants down underwater to do this. One of my friends' kids was a life guard and we were shocked to learn how expensive it is to clean up after that. It wasn't just the boys that did it (why is it always boys? to date the only time a girl has done it was an accident where the kid was sick from something she ate at the snack bar - and they proved that with a lab test. The snack bar got revamped and the girl's family didn't have to pay because it was basically the pool's fault according the the lawyers.), the pool actually banned the parents too. It was a big fuss because they argued that they shouldn't be banned - but they dropped a 12yo off with no supervision and told him to wait for a family to go in and say he was with them, so they got banned too.
Anyway, in my opinion this has to be a huge problem. What do you do to a pool to make it cloudy enough you cannot see the bottom? My aunt ran a swimming pool for almost 30 yrs and NEVER did she even know you COULD make the pool cloudy.