THETFORD TOWNSHIP, Mich. -

Authorities say a couple died and a third person was injured in an explosion and fire at a Genesee County home following a natural gas leak.

The blast happened about 1:50 p.m. Tuesday at the home in Thetford Township.  Those killed are identified as 55-year-old David J. Miller and 56-year-old Susan R. Miller.

Clio Area Fire Chief Gary Domerese says a homeowner was digging with a backhoe during renovations and hit a gas line.

Domerese says authorities are investigating what triggered the blast. He says the homeowner reported the leak to Consumers Energy and a technician arrived, but the home exploded as the technician went to a truck to get tools and summon co-workers.

The home is about 65 miles northwest of Detroit.