Brian was changing out a filter for the house water system (all of our drinking water is filtered here; we fill five gallon bottles (one for us, one for the cats) from the filtration system in the garage).
It's right next to the water heater. I went out to check on Brian's progress and there's a huge mess in the garage. It was the water heater.
Brian headed down to Home Depot to get a new one.
It's always something.