Unknown garbage caused a small fire at an Oak Harbor apartment Tuesday afternoon, according to Oak Harbor Fire Department officials.

Around 1:15 p.m., Oak Harbor Fire Department personnel arrived to an Elwha Street residence after a neighbor reported seeing black smoke coming from the window, according to Fire Chief Ray Merrill. The small, smoldering fire took about three minutes to extinguish but caused an estimated $10,000 in damage, he said. The apartment was unoccupied at the time.

Officials determined the fire was accidental and to have originated from “discarded material in a trash bag” in the bedroom, Merrill said. They are unsure of what was inside the trash bag.

“We couldn’t come up with a definitive cause,” Merrill said.

The heat damage stayed contained to the bedroom, he said, but smoke damage affected the whole apartment. The three other units in the building weren’t impacted and there was no structural damage.

Inside the room, sheet rock, carpet and paint will have to be replaced.

Firefighters from Naval Air Station Whidbey Island provided mutual aid. Merrill said firefighters estimate they used less than 10 gallons of water to put out the fire.