My thoughts regarding the weight of ice and snow are: if the pool is designed to retain 4' - 5' of water, and there is a cover on the pool with an additional 4'-5' of snow on the cover, the weight of the snow would increase the pressure on the side walls of the pool and possibly cause the wall to fail. I was hoping that there were some pool experts out there who might be able to offer some insight.

I've done some research into recommendations from pools manufacturers regarding winterizing, and I can't find any that say to remove the snow from teh cover. In fact, some say not to remove the snow because you can damage the cover. But, isn't there a point where the weight of the snow on tiop of the cover could overstress the wall?

Regarding the fence, I wasn't there to do a code review or home inspection. I was just there to try to determine the cause of the pool failure. At the risk of changing the direction of this post, as I recall there was a guardrail preventing someone from getting onto the deck and into the pool. The door from the house to the pool might have been alarmed, but probably not.