After noticing water coming out of the condensation pipe outside the past couple of weeks, I went into the attic to check. There is rust colored water in the overflow pan of the hot water heater. I could not see any apparent leaks and they were slow enough that I was able to get the water up with a sponge. Also, early this morning as the kids were getting up (and probably turning on the hot water) I heard loud rumbling in the attic. It was 37 degrees this morning. Is the tank gone? How urgent is it?