An off-duty firefighter donned his gear and fought a fire in his own building Thursday night.

About 11 p.m., a deck on top of a four-story condominium building in North Seattle's Pinehurst neighborhood caught fire.

Other residents evacuated the 24-unit building in the 11500 block of 15th Avenue Northeast while Dan Hess went to the roof of the building and fought the blaze with a hose, said Kyle Moore, Seattle Fire Department spokesman.

"He was doing what he knows how to do," Moore said. "He grabbed his fire gear and ran to the roof."

Christine Thomsen, who lives in the building, said she was happy to learn a firefighter lived there, too.

"Today I was thinking I need to write him a thank-you note," she said. "I'm sure [the fire] would have spread. He contained it. He was right there."

Moore said the accidental fire started when smoking material fell between slats of the deck. It spread to a room that housed elevator equipment.

After the fire started, someone flagged down police officers. The officers could see flames shooting from the roof, Moore said.

One police officer broke a window in the building and pulled the alarm, Thomsen said. Then that officer and two others started pounding on doors to alert residents they needed to evacuate.

Two officers had to force open a door after being told there was an elderly tenant inside who was hard of hearing. The officers got her to safety.

Meanwhile, Hess, 29, began fighting the blaze.

The fire didn't extend into any of the condominium units, and all residents evacuated safely, Moore said. Damage was estimated at $50,000 to the building and $10,000 to contents. Cigarette butts were found at the scene.

Autumn Turner, another resident, said other firefighters told her Hess likely kept the fire from burning through to the fourth floor. "He did a fabulous job to make sure it didn't spread further. He definitely saved the top-floor units."

Added resident Sile Harriss: "It was pretty darned cool. I was really, really impressed by how he handled it. It was fabulous."

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com