A bicyclist who was fatally struck by a garbage truck in San Francisco's Mission District this morning was not wearing a helmet, police said.
The collision was reported shortly before 6:45 a.m. at 16th Street and South Van Ness Avenue.
The 21-year-old male bicyclist and the garbage truck were both traveling east on 16th Street when the truck began to make a right turn onto South Van Ness, police spokesman Officer Carlos Manfredi said.
The bicyclist, who was traveling at a high rate of speed, collided with the rear of the truck, Manfredi said.
The cyclist was pronounced dead at the scene. His name is not being released until his family is notified of the death, according to the medical examiner's office.
The mangled white bicycle ended up a block away along a curb on 17th Street. The truck driver stopped and cooperated with authorities, and drugs and alcohol do not appear to be a factor in the collision, police said.
The investigation into the crash and the cleanup of the scene caused police to shut down South Van Ness between 16th and 17th streets for about two hours.
The garbage truck is owned by Recology, which issued a statement following the collision.
"Recology staff responded immediately to this morning's accident and we are fully cooperating with police investigators," the statement said. "Our sincere thoughts and prayers go out to family members of the cyclist."