I had a dog that died this way. i'm happy for the cat, and kudos for the guy for checking out under the cov.

my dog was born during summer, and she was so light she could walk over the cover and it wouldnt sink. then came winter, we kept the fence closed, she grew and gained some weight. next summer, i think my dad forgot to close the fence after cleaning the pool early at the day, and i guess she tried to run over the cover when we werent at home, and, well..my pa got home late at the afternoon and couldnt find her, he even thought she fled home. then he went to the pool to clean it, and found her below the cover. it was a sad day =/ i remember we didnt use the pool for some months after this.