Authorities are investigating a series of traffic collisions in the San Gabriel Valley involving U.S. Secretary of Commerce John Bryson, authorities said Saturday.

Bryson was found unconscious in his vehicle and has been hospitalized, officials said.

Bryson was driving a Lexus in the 400 block of South San Gabriel Boulevard shortly after 5 p.m. Saturday, when he allegedly rear-ended a Buick as it was waiting for a train to pass, according to a statement released by the L.A. County Sheriff's Department and the San Gabriel Police Department.

After briefly stopping to talk to the three men inside the Buick, Bryson left the location in the Lexus and then struck the Buick a second time, authorities said. The men followed Bryson's car and called 911 to ask for police assistance.

Bryson continued to drive his Lexus into Rosemead, which is patrolled by the Los Angeles County Sheriff's Department. There, he allegedly crashed into a second vehicle near the intersection of San Gabriel Boulevard and Hellman Avenue.

There authorities found him alone and unconscious behind the wheel of his car.

Bryson was treated at the scene by Los Angeles County firefighters. Authorities said drugs or alcohol do not appear to have played a role in the crash. They said Bryson was cooperative. He was cited for felony hit and run but was not booked into jail because he had been admitted to the hospital. His condition was not known.