One of my 4 yr old kids back decades ago in the mid 80's, I was our front working on a car. She was in the fenced back yard playing. We had a 4 foot tall above ground pool. The pool water was down lower as it was spring. I never thought what happened next would happen. I hear this noise, like odd crying sound, and I go back and she is standing in the pool water up to her neck. She had climbed the pool filter and fallen in. Water was cold too, not really super cold, more like 60 some degrees. She loved climbing onto everything. God had mercy that day. Never leave a kid unsupervised around any kind of pools.