PHOTOS: Crews responded to a warehouse that was engulfed in flames Sunday afternoon, the Contra Costa County Fire Protection District announced. The warehouse is located at 1200 4th St. where heavy smoke was seen coming out of the building’s roof. The warehouse was vacant at the time of the fire, officials said. No injuries were reported. Crews were on scene for “several hours” in response to the fire. Video from the Contra Costa County Fire Protection District shows crews extinguishing the fire. County fire officials first tweeted about the fire at 4:24 p.m. on Sunday. The cause of the fire is unknown at this time and will be under investigation.