SAN DIEGO -  

A 24-year-old man was hospitalized Sunday after he hit his head on a reef while cliff diving off Sunset Cliffs.

The incident occurred at about 3:15 p.m. when the tide was low, according to lifeguards.

Lifeguards said the man was cliff diving when he hit his head on a reef and was knocked unconscious. A passerby called 911.

The man was then airlifted to a local hospital to be treated. His condition and the extent of his injuries were not immediately available.

Lifeguards said cliff diving or jumping is not allowed. Offenders face a $400 fine if caught by a police officer or lifeguard.