Here is footage of a house fire in Tuscon from the 24th. The fire was in a remote area and was well involved by the time the firefighters got to the scene. The fire was on Webster Road, near Cloud and Sabino Canyon roads.
The news reports that propane tanks exploded. That may the be case, but after watching the video I think it sounds like ammunition exploding as well. In the first video you can watch the firefighters jump at the first explosion as they advance a hoseline to the front of the house.
Fire Critic An Unadulterated View of the Fire Service