Two members of the Bismarck Police Department helped a woman climb out of a basement window to escape a duplex fire Monday morning in east Bismarck.

Bismarck police officer Charles Wegener and traffic marker Dave Hess were first on the scene of the fire at 402 21st St., at the intersection of Rosser Avenue and 21st Street.

"There was a woman coming out of a basement window," Wegener said.

"We gave her an assist and carried her away from the burning house."

The woman, who was not identified, was the only person at home in the duplex at the time of the fire, said Capt. Barry Dutton, acting battalion chief for the Bismarck Fire Department.

She was treated and released at a Bismarck hospital, Dutton added.

"She appeared to have burns on her left arm," Wegener said. She also was suffering from smoke inhalation, Dutton said.

The woman couldn't get out through the bedroom door, so she was trying to escape through the window, Dutton added.

The cause of the fire, which originated in a bedroom, remains under investigation, and firefighters contained the blaze to the bedroom, Dutton said.

Smoke was pouring out of an upper window and the basement window that the woman crawled out of, Wegener said.

A black scorch mark scarred the outside wall at the back of the duplex near the window from which the woman escaped.

Firefighters could be seen carrying a mattress outside and dousing it with water.

The extent of the damage was unknown, said Mike Walsh, one of the building's owners, adding that a preliminary report from firefighters indicated there was no structural damage.

(Tribune reporter Katie Brown contributed to this story. Reach reporter Richard Hinton at 250-8256 or outdoors@bismarcktribune.net.)