First off, my heart goes out to this family... this is a tragic loss they will never forgive themselves for, both the parents as well as the ones watching the child.
Here in Fl, when a new pool is being built, it is code that there must be some sort of alarm or baby gate installed with it. I might be flamed for saying this, but my personal feelings on alarms are, by the time it goes off, that child is already in the water. Sure, it is better than nothing, but it would be better if it was a back up to a baby gate. Have the gate installed, then the alarm as the back up. If this is your home and your child.. isn't it worth the money
Water is something that cannot be taken lightly. One ounce is all it takes to drown... and just because they can swim doesn't mean they can't drown. Don't be fooled by that.
I have had a pool since my youngest was 18 months old. My older were nearly 6 & 8. I have a lania that is closed in with aluminum on the bottom and vinyl windows on the top. (totally seperate from my pool deck) The handles were moved up to the top of the door. Then there was a baby gate installed around the pool in the event they got out of the lanai. Then the pool itself is also screened in with the door handles on the top of the doors, and my yard is fenced in. (yes, Fort Knox) All three were able to swim, including the baby!
They are now 14, 18 & 20. We have one rule that is still a must and it goes for all of us.. it is the buddy system. We never swim alone. You want to swim, you swim when someone else is out there with you! You never know if you will get a cramp, hit your head etc.. drowning is not only for babies.
There are so many things that you need to think of and cover when dealing with a pool.. not just when you aren't there..and not just when they cannot swim.. it can happen when you are out there, it can happen to those that can swim. You just can never tell. Set your rules and stick to them. Get a cordless phone that is to be out by your pool at all times. I have one of the extra ones that doesn't need a phone jack.. plugs into the electrical outlet. That stays on my lanai. When they go out to the pool, that phone, or the cell phone goes with them! Always be sure to lock up the baby gates when you leave the pool area. My kids are older, so we took ours down. When they were younger, that was a must... the barrier had to be closed behind us and locked.. the doors had to be closed and locked..
We had to put our barrier up when we got one of our dogs, he used to jump into the pool and couldn't swim. We were afraid he was going to drown. So for a few months, after years of not dealing with the barrier and locks, we were back to doing it.. so the dog would not drown! Which is something people do not think of either.....