ANTIOCH -- A Brentwood man injured in a one-car wreck on Marsh Creek Road is expected to survive his injuries, a California Highway Patrol officer said Tuesday.

Police are still investigating why the silver Chevy Malibu ran off the road and into a ditch about a mile from Deer Valley Road at 2:11 p.m. on Monday, CHP Officer and spokesman John Fransen said. Officers who first arrived to the scene found the Malibu on its roof in the ditch and a man inside bleeding profusely, Fransen said.

Officers originally said the driver was female, but Fransen amended that Monday, saying the driver of the Malibu was a 20-year-old man. The man never lost consciousness but was taken to John Muir Medical Center by medical helicopter, Fransen said.

It is not known yet whether alcohol or other drugs played a role in the accident, Fransen said. It was not known immediately how long the man was expected to remain in the hospital.

Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH.