Two adults were injured and a family dog died in an early morning house fire north of Bothell Sunday, according to a Snohomish County Fire District 1 press release.

The fire was reported just before 6 a.m. at a single-story home in the 21200 block of 1st Avenue West in unincorporated Snohomish County. The fire appears to have started in the laundry room.

“The room was so heavily damaged the investigator was unable to determine exactly how the fire started, but noted it appeared to be accidental,” said Leslie Hynes, public information officer for Snohomish County Fire District 1, in a press release.

Six people were in the house at the time of the fire: a man and a woman, her teenage son and three of his friends, all teenage boys. All were asleep when the fire started. One of the house guests told firefighters he woke up and discovered the fire. He alerted the others. The boys safely exited through the front door. The couple climbed out a bedroom window.

The man and the woman both inhaled smoke as they escaped. Firefighters transported both of them to an area hospital. They have since been treated and released. Their injuries did not appear to be life-threatening. Firefighters also evaluated the woman’s son at the scene for exposure to smoke. There were no other injuries.

“The first 911 calls reported large flames coming from the house,” said Hynes in the press release. “When the first firefighters arrived, the back of the house was engulfed and the fire was through the roof.”

Firefighters from Fire Districts 1 and 7, Lynnwood and Bothell responded. Fire conditions and the threat of structural collapse made it unsafe for firefighters to enter the home so they attacked the fire from the outside. It took firefighters about 45 minutes to get the fire under control.

The fire left the home uninhabitable and displaced four residents: the couple injured in the fire, the woman’s son and her daughter, who was away at the time of the fire. Support 7 and Red Cross have been contacted to assist the family.

“No one reported hearing a smoke alarm,” Hynes said in the release. “We’re just fortunate someone woke up in time and everyone got out of the house, but it’s best not to leave that to chance. Smoke alarms are your early-warning system to give you time to get out quickly.”

Fire District 1 recommends installing smoke alarms in every sleeping room and outside each separate sleeping area, to install them on every level of the home and to install them in the basement. The fire district also recommends testing the alarms at least once a month by pressing the test button on the device. Finally, the fire district recommends replacing smoke alarms that are 10 years old.