This was a 3400 sq ft house in a McMansion neighborhood with a private golf course here near Charlottesville. The owners were in Portugal and had a neighbor caring for their dog. She went over at dinnertime and smelled gas, and called another neighbor to help. As he was walking there, it exploded. Killed her, critically injured him on the street, and left 12 neighboring houses uninhabitable. Underground propane tank, unknown where the leak was, maybe ATF will find source. The largest remaining rubble are single bricks.
Detectors are 20-50 bucks. Get one tomorrow if you have propane or ng.