A couple of houses ago - was walking in the basement and heard a hiss -
stopped and took another step - was hit by a fine spray of water. Pin
hole in galvanized hot water pipe. Tried to replace this section -
when I put the wrenches on it - broke threads - ended up having to
replace all the pipes in the house.

If you do it yourself - be careful not to burn the place down when
sweating copper joints - keep some firefighting water handy.