Three people died this morning in a fiery chain-reaction crash that shut down Route 301 in Brandywine, Md., for hours during the morning rush hour, according to Maryland State Police.

At least two other seriously injured people were flown from the scene by helicopter, according to the Prince George's County Fire Department.

Traffic backed up for miles on 301 as police closed the busy road that carries commuters from Southern Maryland into the Washington area. By 11 a.m. one lane of traffic was allowed to pass in each direction.

The accident, which occurred shortly after 5 a.m., involved two trucks and several cars, police said. It occurred just north of the intersection of 301 and Cedarville Road near the Prince George's County-Charles County line when two vehicles crossed the median, colliding with traffic moving in the opposite direction.

Cpl. Rob Moroney, a spokesman for the Maryland State Police, said a taxicab was traveling in the northbound lanes of 301 when it veered across the median as it attempted to avoid hitting a disabled truck stopped in the fast lane.

A dump truck driver in the southbound lane, reacting to the taxi crossing the median, then lost control, crossed the median itself into the northbound lanes, where it hit a car and a truck.

The collision triggered a fire in the pileup of the cars and the dump truck.