A Sanford firefighter tweaked his knee while fighting an early Tuesday morning structure fire, but everyone who lived in the home got out safely.

Capt. Scott Lizotte said the firefighter was pulling a hose when he slipped and tweaked his knee. The injury is not considered serious.

Lizotte said the fire at 451 School St. began in the home’s chimney before it extended into a wall. The fire was quickly brought under control.

The fire was reported at 12:03 a.m.