Firefighters are battling a three-alarm fire Thursday in a large commercial building in Vallejo. The fire is located near the intersection of Broadway and Sharon Street on the western edge of the city near state Highway 29. As of 6 p.m., the fire remains at three alarms. A Vallejo fire spokesperson said the commercial building likely houses a large number of vehicles. Firefighters from American Canyon, Benicia and Fairfield are assisting Vallejo firefighters. A lumber yard is located west of the fire location and a mobile home park is one block north, so firefighters are taking preventative measures so the flames do not spread. There are no further details at this time.