jim whitehead wrote so after shutting off the water and mopping up i was left to ponder what are the odds of having mechanical failure of a large rectangular porcelain bowl in the absence of any visible stressors like someone striking it with a sledgehammer we hadn t done anything unusual to the toilet in the recent all it takes is an overtorqued nut e g at the water intake entrance to stress the porcelain and you ve got a time bomb waiting to go off of course if you re lucky you ll overtorque it enough that the tank will break right away while you still have the water intake shut off joe 