One bicyclist suffered serious injuries to the head after colliding with another bicyclist in Clairemont on Wednesday.

According to the San Diego Police Department (SDPD), one rider attempted to pass another cyclist in the bike lane, resulting in the crash.

The incident around happened 1:50 p.m. on Balboa Avenue near Clairemont Drive.

Both bicyclists were not wearing helmets, police said.

One suffered multiple skull fractures and he is not expected to survive. The other bicyclists, identified to be an 18-year old man, has injuries to his spine and feet. Both were transported to Scripps La Jolla Hospital.

The eastbound lanes of Balboa Avenue between the 4200 block and the 5000 block was shut down to traffic. The closure was expected to last for about an hour.

No other information was immediately available.