I nvestigators have determined that a lawnmower cutting dry grass sparked a fire that burned 17 acres near homes in Medford's east hills Thursday.

I nvestigators have determined that a lawnmower cutting dry grass sparked a fire that burned 17 acres near homes in Medford's east hills Thursday.

The fire started at 5350 Aerial Heights Drive at about 3:15 p.m. Fire Marshal Greg Kleinberg of the Medford Fire Department said the mower's blade likely hit a rock, sending out a spark that landed in the dry grass.

Investigators found no mechanical problems with the mower that led them to believe it caused the blaze.

The residents could be liable to pay for the damages of the fire, Kleinberg said.

"If the other property owners decide to make them responsible — if they feel it damaged their property — they can be held liable for any damages," he said.

He said the residents of the home called emergency services and tried to extinguish the fire, but it quickly grew out of their hands.

"They tried to pull some hoses down the hill and put some water on it," Kleinberg said.

Wind fanned the fire and carried it through low brush on the hill, headed toward homes on Cherry Lane, where crews positioned themselves to stop the flames. One small spot fire was found on the east side of Cherry Lane, but crews quickly extinguished it before it damaged any structures.

The blaze knocked out power to nearly 1,000 homes in the area and traffic lights on North Phoenix and East Barnett roads just before 4 p.m. Pacific Power restored power to the area at 4:41 p.m., Pacific Power spokesman Monte Mendenhall said.

The fire sent a column of smoke above the hills in east Medford that was visible from downtown. Crews from Medford, Jackson County fire districts 5 and 3 and the Oregon Department of Forestry responded to the call.

Two helicopters that dumped water and an air tanker that dropped retardant on the blaze were pulled from the Double Day fire burning just south of Butte Falls to battle the blaze.

Kleinberg said people should be cautious mowing when fire danger is high.

"Especially on hillsides and wildfire hazard areas, we would recommend following (Oregon Department of Forestry) rules," he said. "Cutting green grass is different than cutting dried weeds and grass."