Possible leak in new pool still under construction after pouring decking

The pool installer poured our concrete decking on Monday and Wednesday of last week. Since then, I have noticed the water level seems to have dropped in our fiberglass pool. Our temps have cooled off a little bit, so I do not think it is due to evaporation. I have added water the last couple of days, only to find the level dropped in the morning. Any ideas? I am wondering if they caused a leak in a line while pouring concrete? Obviously, it is the responsibility of the pool builder at this point, but I am curious.

Found the leak. Coming from a connection at the pump. We have a 4 speed pump and it only leaks when the pump speed is increased beyond the lowest setting.