A fire caused by an electrical problem in a refrigerator swept through a home early Thursday, killing seven family members who were overcome by smoke before they could escape, officials said.

A neighbor reported the fire at 5 a.m. Emergency crews who arrived minutes later found the one-story house in flames, Assistant City Manager Mike Brice said.

Brice said the home had no working smoke detectors. One of those killed was found in a bathroom. The others were found in bedrooms. Some were near windows, apparently trying to escape before they were overcome, he said.

Firefighters pulled all seven victims from the burning house but were unable to resuscitate any of them. Investigators later traced the fire to a refrigerator fan motor that apparently overheated, Brice said.

"It is stunning to all of us when you lose this many people," he said. "It's a real tragedy."

Chickasha is a city of 17,000 about 40 miles southwest of Oklahoma City. Brice said it was the town's deadliest fire to date.

The victims were identified as Thomas Raby, 33, Cindy McCurley, 34, and their children: Cicily, 12; Casey, 9; Casandra, 8; Chelsea 7; and Sidney, 1.