Several streets in Mission Beach were closed for hours as officers investigated a hit-and-run involving a bicyclist.
San Diego Police said the incident happened at approximately 9:50 a.m. on westbound West Mission Bay Drive and Gleason Road, where a car fled after it hit a bicyclist.
A Good Samaritan followed the car and got a license plate, police said.
The bicyclist was taken to the hospital for a shoulder injury but was later found to have suffered a brain bleed, a major injury.
The streets reopened shortly after 12 p.m.
No further information was immediately available.
