if it looks bad, every waterheater is at least supposed to have a cutoff valve specifically for it. on the coldwater pipe that attaches to the top. ive seen a few without it though
laziness, jerkiness. i dunno :o most of them spring a leak on the top or the bottom of the tank. i dun think anyone cares why this happens :o if youre worried, cut the water to it and turn the waterheater down. youll have no hot water
and whatevers in there will leak out. if youre feeling bold and its possible, once you cut the water you can drain the tank yourself witha hose. should have a standard hosetype connector on the bottom. often these are plastic and brittle though sos there is some element of danger. :O turn the waterheater down to vacationmode if you plan to do anythin to it at all.
its ok to put towels around it. not stacked up against it or stuffed under it :o but around it. hopefully its not so bad that you cant survive a couple days
should at least locate the cutoff if the bottom falls out. 50 gallons is bad, but not as bad as the infinite :o