"I am wondering what is the safe capacity of the pool? and how many from a family of moer than 100 were trying to use it?"
It's a valid question, but had that been taken into account and explained to the family, I'm sure there would not have been a lawsuit, but rather a way to work around the large number of children (perhaps letting groups at a time in the pool?).
Based on what? Ive seen suit for dumber things and so have you.