SEDRO-WOOLLEY — A fire enveloped a Sedro-Woolley residence Wednesday morning, killing one and injuring one.

Mark Anderson, deputy fire marshal for Skagit County, said a woman in her 60s is in critical condition at Harborview Medical Center in Seattle.

A man in his 70s died at the scene, he said.

Firefighters responded to reports of a mobile home on fire about 2 a.m. Wednesday off Wicker Road in Sedro-Woolley, he said.

They found a heavily engulfed single-wide mobile home, and recovered the two victims.

The cause has not been determined, though investigators found a space heater plugged into a thin extension cord that may have contributed, Anderson said.

Both the Sedro-Woolley Fire Department and Fire District 8 responded, he said.