Boulder firefighters were able to safely get a father and son out of their house at 3544 Kirkwood Place after it caught fire early this morning, according to officials.

Firefighters responded to the house after a neighbor reported seeing fire outside the house at 1:23 a.m. today, according to Boulder Fire Department spokeswoman Kim Kobel.

The fire then spread to the attic of the house. A father and son who lived in the house were inside sleeping and did not know there was a fire until firefighters were able to evacuate them from the building. Kobel said there were smoke detectors in the house but that they did not go off for some reason.

The father and son were checked out by paramedics on scene and cleared. No other injuries were reported, according to Kobel.

The cause of the fire is still under investigation, though Kobel said officials believe the blaze started outside the house before spreading to the house. Kobel did not have an estimate on damages.

Kobel also urged residents to remember to test their smoke detectors and also to change out the batteries.