WASHINGTON — The Fairfax County police are investigating the death of a man in Herndon, Virginia, who they think may have passed out behind the wheel.

The police said in a statement that Cory Boback, 30, of Sterling, died a short time after he was found unconscious behind the wheel of a 1993 Mazda 626, partway down an embankment on the eastbound side of Hiddenbrook Drive, before Dranesville Road, at about 9 p.m. Wednesday.

Fairfax County Fire and Rescue took Boback to a hospital in what the police described as life-threatening condition. He was pronounced dead there later.

The police said their preliminary investigation suggests the car was stopped at the light on Hiddenbrook Drive at Dranesville Road; that Boback may have passed out, and that the car may have then rolled backward down the embankment without striking anything.

They’re still investigating, but say speed wasn’t a factor.

The medical examiner will conduct an autopsy, the police said, and will determine the cause of death.

If you know anything about the case, the police ask you to call them at 703-691-2131, by going to the Crime Solvers website www.fairfaxcrimesolvers.org or texting a tip by texting “TIP187” plus your message to CRIMES (274637).