The purpose of a smoke detector in a house is to notify the residents of the first sign of smoke. But when the alarm itself is on fire, it's difficult for it to perform its function.

That was the case when Galen Hanson and Carmen Hickle returned to their home at 1400 North 4th St. Friday evening.

After discovering the source, they called 911 emergency response. At roughly 8:42, the police and fire department responded.

The residents were able to put out the burning detector with a fire extinguisher before the fire department arrived.

Fire fighters determined the fire detector had an electrical malfunction that caused the device to combust, said Sgt. Scott Meyers of the Bismarck Police.

No one was hurt and damage was minimal.