PONTIAC - A suspicious blaze that badly damaged a mobile home Thursday morning in Pontiac started as a mattress fire, a fire lieutenant said Friday.

Pontiac Fire Lt. Scott Runyon said Friday there was nothing near the mattress that could have ignited it on its own.

"It's suspicious in nature, due to there's no ignition sources in the area," Runyon said. "And it is still under investigation."

Nobody was injured in the fire that broke out about 9:15 a.m. at the home owned by Larry Walker at 37 Sterling Estates, which is about half a mile south of the Illinois State Police District 6 headquarters and west of Old Airport Road. The fire was contained to a bedroom and nobody was home, the firefighters previously said.