Rescuers pulled a man's body from the rubble late Wednesday afternoon. Crews were looking for one other person who police say is an employees of the furniture store.
Residents in homes and businesses were evacuated. The huge blast occurred at about 9 a.m. It was felt as far as a mile away, shattering windows of nearby buildings.
The one-story once-sprawling building was reduced to a pile of wood, crumbled drywall, and twisted metal with broken bits of furniture scattered about.
Consumers Energy received a call of a possible gas leak in the area several hours before the blast, and a worker had been trying to track down the source when the building exploded.
An official for the utility said the gas main to the building was shut off Wednesday morning and another line in the area was closed later in the day after utility crews found a second leak Wednesday afternoon.
The Associated Press contributed to this report.