A resident at the duplex at 121 Morton Ave. is distraught following Thursday's fire at his home.

A Thursday morning fire in a Morton Avenue duplex was caused by a space heater, fire officials said.

No one was home and no one was injured in the fire about 11:30 a.m.

Fire crews were met with heavy smoke coming out of both apartments. They forced in a door to the upstairs apartment to get inside. It was extinguished by city firefighters in about 7 minutes

The blaze started in a bedroom of the downstairs apartment, said Capt. Jim Kaufman of the Butler Fire Department.

The tenant had a space heater plugged into a nongrounded extension cord, which was beneath a carpet, Kaufman said.

“It was pretty obvious what was going on, we were able to trace the origin pretty easily,” he said.

After talking to the downstairs tenants, who said they didn't have any open flames burning or other appliances running, the fire was ruled accidental and no law enforcement was notified, Kaufman said.

The first floor apartment, which is now uninhabitable, was occupied by two people who are being aided by American Red Cross.

Damage was estimated by the fire department as $20,000 to the structure and $10,000 to the contents.

The second floor apartment was occupied, but the tenants there were in the process of moving out, Kaufman said. The second floor has smoke damage, but is still habitable.

The building, 121 Morton Ave., is owned by Joseph Muscik and Mariann Snyder, according to Butler County real estate records.

Eagle Staff writer Jim Smith contributed to this report.