Bicyclist Injured After Colliding With Tree

are investigating how a 51-year-old man riding a bicycle crashed into a tree early Sunday.

The Livermore man was found unconscious by emergency crews about 1:55 a.m. He was lying in the No. 2 lane of Murrieta Boulevard near East Jack London Boulevard, Sgt. Kevin Santin said.

The man was not wearing a helmet and suffered head trauma, Santin said.

He was transported to Eden Medical Center in Castro Valley. As of Sunday night, he had not regained consciousness, officials said.