MADISON, Wis. (AP) — Investigators are trying to determine what triggered an explosion that destroyed a house in Madison.

The house exploded and caught fire Wednesday afternoon. Some neighboring homes were also damaged by the blast. Residents of eight homes close to the explosion have been displaced.

Officials say a firefighter and a civilian in the area at the time of blast suffered minor injuries. The owners of the house were away, but firefighters initially searched the rubble, not knowing if anyone was inside when the house exploded.