My first thought was natural gas leak but no one has reported smelling gas as of yet.
My town had a gas leak explosion in the 1990s. The gas leaked into the basement from a crack in an old line under the sidewalk. No one noticed the smell. When the furnace kicked on, a large 2 story story building was leveled and killed the occupants. It blew some of the windows out of my house. I was 9 houses away from the one that exploded.