VIRGINIA BEACH, Va. (WAVY) — Virginia Beach fire officials say a small fire in the bedroom of a house on Heritage Avenue was caused by a person smoking in bed.

Fire officials are using the incident as a warning to residents to be careful while smoking inside their home.

Fire crews responded to the home in the 1500 block of Heritage Avenue around 2 a.m. Monday morning, according to a news release.

Firefighters arrived to find a woman outside who said her adult son was still inside the house, which was filled with smoke.

Firefighters entered the house and found the man awake inside a bedroom. A mattress was smoldering in the room.

Investigation showed the man may have fallen asleep while smoking in bed. When his mother heard the smoke alarm, she called 911 and went outside.

Her son refused to leave the house at first, but was later treated outside for minor injuries. He refused to be transported to a hospital for further evaluation, the release said.

According to the release, smoking is the third leading cause of residential fires in the United States, and the leading cause of home fire deaths between 2012 and 2016.

About 34 percent of fatalities caused by smoking-related fires started in the bedroom.

“The fire at Heritage Avenue this morning was contained to the mattress and no one was seriously injured but had it not been for a working smoke alarm, things might have been worse,” the release said.