WASHINGTON — A man is in critical condition after he lost control of his vehicle on the Key Bridge, struck a curb, flipped over and was ejected early Thursday.

Arlington County police spokesman Dustin Sternbeck says the man suffered life-threatening injuries when he was thrown 30 feet from his vehicle around 2:06 a.m. He was taken to George Washington University Hospital.

Someone passing by stopped, and along with an officer, gave the man CPR.

Speeding and alcohol are believed to be factors in the crash.

Traffic had to be diverted from the Key Bridge to the George Washington Memorial Parkway for 4 1/2 hours.

Police have not released the man’s identity.