MITCHELL, S.D. (AP) - Investigators say the cause of last weekend's natural gas explosion at a house in Mitchell is now labeled as suspicious.
The city's chief of public safety says evidence at the scene leads authorities to believe the explosion was not accidental.
Additional specialists could be called in to assist with the investigation.
Nobody was home at the time of the explosion and no injuries were reported.
Authorities say the blast moved the walls of the home and knocked its front porch away from its main structure.