Accident shuts down Beltway lanes A tractor-trailer overturned Wednesday night on the Capital Beltway, which forced authorities to shut down six lanes in Prince George's County after fuel spilled from gas tanks on board. The vehicle flipped into the median near Central Avenue about 9:30 p.m., and officials shut down three lanes on both the inner and outer loops, Prince George's County fire and Maryland State Police officials said. Late last night, traffic was reopened to an additional lane in each direction. Fuel leaked from the saddle tanks of the semi and county hazmat units were called to the scene to handle the clean-up. Each tank holds about 75 gallons of fuel, but it was not immediately clear how much had spilled or how long it would take to reopen all lanes of traffic, said Mark Brady, a fire department spokesman. This report has been udpated.