When I saw the first part of the thread title (before the part about the fire station) I was going to say a fire house burning down.....it happened once when I was stationed in Korea.
Someone once told me it was like rain on your wedding day, but I think its like a free ride after you've already paid. Not entirely sure.
Irony is the use of words expressing something other than their literal intention. In this case, a fire department actually being a department on fire. Alanis Morrisette notwithstanding.