PITTSBURG -- A 50-year-old man riding his bicycle to work was in grave condition after colliding head-on with a car, police said Friday.

The bicyclist was riding northbound on Loveridge Road around 4:45 a.m. Wednesday morning against southbound traffic when he ran into a four-door sedan, Pittsburg police Lt. Ron Raman said. He was out that early because he was on his way to work, Raman said.

The driver of the sedan stopped and cooperated with police, and an investigation showed that no drugs or alcohol were involved, Raman said. The driver was not speeding, either, he said.

"This was nothing but a tragic accident," Raman said. "The driver of the vehicle was not at fault. And obviously, our prayers are with the family of the injured man."

The man remained in grave condition in a hospital Friday afternoon, Raman said.

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