A fire in Ross destroyed the Audio One Building in the 2900 block of Babcock Boulevard early today.

Two businesses -- an auto detailing shop and a mechanic's shop -- were destroyed. The Allegheny County Fire Marshal's Office estimated $300,000 in damage from the fire, including three cars that were inside. The fire was called in by a passerby at about 12:30 a.m., reported the shift commander from the county 911 center.

The fire started near the roof of the building, according to the fire marshal's office. Firefighters broke into the building, and when the fire began to ventilate through the roof, crews tried to manage the blaze from the building's exterior.

A guard dog on the premises was killed. Fire officials reported that one minor burn and one eye irritation were suffered by local firefighters. The cause of the fire is still under investigation.