Whoa-ho-ho, we had a mess in the basement this morning. Last night my Mom was telling me that she was hearing this weird sound, but when I tried to hear what she was talking about I wasn't picking up anything. This morning she was hearing it again and believed it was coming from downstairs, so I went down to look.
Turns out that there was something wrong with the water heater. All this steam was rising off of it, gathering on the massive pipe overhead, then coming back down as water. By the time I found it the furnace room, most of the adjoining hallway, and a small part of my Dad's (currently) unused office had been flooded.
A repairman came by and dealt with the issue, and told us that the water heater was partially corroded due to age and that there had been this hole in it. The heater's around 22 years old, and he implied that we'll likely need to get it replaced before too long. In the meantime, my Mom ran damage control via a mop, a fan and air circulation. This'll take a while to resolve.
Man, what a way to start the day. ()^_^