Kohler one piece Rialto toilets

We installed 3 Kohler one piece Rialto toilets around 1983. Last year while I was on vacation the valve handle in one of the toilets fractured and the water kept on running. Nobody was home and the water ran for about 10 days. The water ran out of the tank and flooded the whole house. It seems that the overflow pipe could not handle the volume of water that was flowing into the tank. There are three holes in the back of the tank just above the water line. The water was gushing out of these holes. The toilet was on the second floor of the house. The result was that the entire first floor and basement were damaged. Has anybody else encountered this problem?

I have seen similar problems while people were on vacation and I recomend you close your main valve every time you take a vaca. Be sure the valve is operational by opening a faucet and checking that the water stops running.

Turn off the water heater if you turn off the water.

kohler recalled the flush valves with the small round hole and replaced with the rectangular for this very reason.