A firefighter was injured while working to put out a fire in a ranch-style home in the 6000 block of Muncaster Mill Road Saturday morning, said Assistant Chief Scott Graham of the Montgomery County Fire and Rescue Service.

Traffic cameras first alerted dispatchers to the fire—when they noticed smoke coming from the Derwood home. The county fire service was called at around 5:30 a.m.

When units arrived on the scene, they found a basement fire that had burned through the first floor, creating a hole. While extinguishing the fire, a firefighter fell through the floor and was extricated from the basement by firefighters working in the basement, according to Graham.

The firefighter has minor injuries and was taken to a local hospital for evaluation.

The fire was brought under control in about 20 minutes. The origin and cause of is under investigation.