1. All the sand that they added to the beach over the years has settled into the underground springs and clogged them up.
2. As evidenced by the pools of tar I found, there are underground tar supplies that seep out and fill up the hole at the bottom of the lake. For some reason, probably global warming, the tar stopped oozing and now the hole is open.
3. When Patrick Swayze was filming Dirty Dancing, he left part of his soul in the lake. Now that he is battling for his life, the lake is also battling for its own. The only solution is for Patrick to die to release his soul completely and break the bond with the lake. Or get better and revitalize the lake through strengthening his soul.
What is your theory?