I interview operator and she said she was pulling tubers when she noticed the boat was taking on water. She was able to wave over a passing boat and was towed into shore. They were able to make it to the end of the pier before the stern of the boat sank to the bottom of the lake. She said this is the third time the boat sank but the other two times the boat was tied up to their pier. OPerator also advised that everyone on board had a pfd but nobody had to use them. 

patona bay completed the inspection of the boat and contributed the cause of the accident to the failing of the seam of the top deck and the hull. The failed seam took on water faster than the bilge pump could pump the water out causing it to sink very rapidly.
North Webster