Fairfax County police are investigating a six-car accident that they say began when a trash truck driver rear-ended a car, veered into oncoming traffic, setting off a chain reaction of other crashes that ended at a gas station and injured several people.

Officer Don Gotthardt, a police spokesman, said investigators believe the truck driver may have had a medical condition that caused the Thursday evening accident at a Sunoco gas station on Braddock Road. Authorities have not released the name of the driver.

Gotthardt said five people were injured in the accident, which took place directly across from George Mason University. Two people remained in the hospital Friday with non-life threatening injuries.

Police said the trash truck driver was driving a 2007 Mitsubishi Box Truck west on Braddock Road about a quarter mile from the gas station, when it rear-ended a car at 4:44 p.m.

The truck hit the back of a 2010 Toyota Rav4, and then crossed a median into oncoming traffic and struck a cross walk signal. Gotthardt said the trash truck went on to hit two parked vehicles — a SUV and van — and a tree.

It was there where police believe a chain reaction began.

The van struck two pedestrians in the gas station parking lot, and then struck a two vehicles — a Toyota Tacoma and a Isuzu Box Truck — parked at gas pumps.

Gotthardt said one of those vehicles crashed into a gas pump. Firefighters ensured that all the gas pumps were off, but the pump sustained heavy damage, he said. The gas station was still closed Friday because of the accident.

He said it appears that neither speed nor alcohol were factors in the crash.

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