A fire that broke out early Thursday morning in a room of the Redmond Super 8 Motel was stopped from spreading by an automated sprinkler, but not before guests were evacuated, officials said. Investigators determined it was caused by improper disposal of smoking materials.

Redmond Fire and Rescue crews were called around 2:20 a.m. to a first-floor room at the three-story motel on Southwest 21^st Place, near the Redmond Airport, Captain Ken Brown said.

Motel staff was assisting in the evacuation of guests, helped by fire and police, as fire alarms sounded. The automated fire sprinkler system activated and confined the fire to the one room, where initial reporters said the carpet and mattress were engulfed in flames, Brown said.

Crews made entry into the room, put out the fire, checked for any extension into other rooms and searched each floor and room for any other occupants, he said.

They ventilated the smoke and restored sprinkler and alarm systems, allowing guests to return to their rooms within two hours of the call, except for those near the affected room, who were moved elsewhere in the motel.

Damages were estimated at $3,000 to $5,000. Deputy Fire Marshal Clara Butler said the accidental cause of the fire was determined to be improper disposal of smoking materials.

Mutual-aid assistance was provided by the Bend and Black Butte Ranch fire agencies, along with Redmond police and Pacific Power.