A bicyclist suffered unknown injuries Monday when he was struck by a car on Mendocino Avenue near downtown Santa Rosa.

The man was riding south on the street just before 5:45 p.m. when he was hit.

Bystanders directed traffic around the man, who lay on his side in front of a blue Toyota, awake but in visible pain. He wasn't wearing a helmet.

"Stay strong, Andrew," yelled a man as he waved cars around the crash scene.

Ambulance crews loaded the man onto a stretcher and took him away.

The woman behind the wheel cried as police arrived. Bystanders gathered on the sidewalk and officers began interviewing witnesses.

The circumstances of the crash were unclear. A witness told an officer the cyclist swerved into the path of the driver.

Another woman said the cyclist may have swerved to avoid an opening door of a station wagon that had just parked at a meter.

Mendocino Avenue is particularly dangerous during the congested commute hours, said Marge Fernandez, who works downtown and walked by moments after the crash.

"Just crossing the street is dangerous," Fernandez said.