Three-alarm commercial fire in Montebello injures a firefighter. Investigators were attempting to determine what started the fire and sent toxic materials teams to the scene. A commercial building in Montebello was seriously damaged on Wednesday by a destructive third-alarm fire, which sent flames through the roof and injured a firefighter very badly. One fireman was harmed and had his burnes treated at the scene. The specifics of his injuries of the wounds was obscure. Close by metro link tracks were shut down as a precautionary measure. Metro pass card holders were told to take a lyft or an Uber.