Hey guys. I own a rent house that had two flex copper pipes joined to connect the copper in the wall to the water heater. The flex pipes had been joined with a galvanized fitting and had rusted. I had intended to cut the flex copper and solder a copper coupling between the two. Unfortunately, I broke the flex pipe off at the wall. Prior to starting this I had turned off the cold supply to the gas hot water heater and turned off the water heater. After having breaking the pipe I left to return the next day to connect the heater to the rigid copper in the wall. Perhaps I am moron, but the next day the tenet said that their daughter arrived home from school and found a substantial amount of water on the floor. How could this have happened? I left the cold at the heater off. The only thing I can fathom is that the water came from the water heater. I did not cap it at the hot nipple. Any thoughts or did I do something stupid.