Update 9:31 p.m: The fire has been declared under control. A firefighter at the scene described the house as "totally gutted." Smoke or fire damage is visible from most exterior windows. All three floors of the house and a finished basement were affected.

The fire marshal in charge of the scene said it will be at least "a few hours" before information on the possible cause of the fire will be available.

Earlier story follows.

Three fire companies are at the scene of a fire on Avondale Road in West Norriton. The fire at one point involved all three floors of the apparent two-and-a-half story dwelling, but has mostly been contained to an area of the first floor.

A ladder truck was still accessing areas on the upper floors of the house, and firefighters were seen working on a porch area on the side of the structure.

According to a firefighter who declined to be named, nobody was home at the time the fire started. The fire was called in to 911 by a neighbor.

An earlier BNN report described "heavy fire on all three floors" of the dwelling.

Norristown Fire Company, Jefferson Fire Company No. 1, Lower Providence Fire Company and West Norriton police are at the scene.

A Patch reporter is at the scene. We'll post additional details as they become available.