The collapsed area is by Flat Rock, below the 12000 block of N. Torrey Pines Road, according to a docent at the state park.
A park employee found the cliff collapse around 8 a.m. this morning and because no camping is allowed, officials do not believe there are any victims, she said.
The San Diego sheriff's search and rescue team is on the scene and checking out the collapse as a precaution, said sheriff's Lt. Hope Andrews.
Flat Rock is also where a 57-year-old tourist died last August when debris from a sea-bluff collapsed on him in the middle of the day.
Three to five cubic yards of rock and dirt fell about 25 feet onto Robert Mellone, of Henderson, Nev., partially burying him. Mellone's relatives and other beachgoers dug him out from under basketball-sized stones and earth. Mellone died at the hospital about an hour later.
The cliffs above Black's Beach are treacherous and frequently dump tons of boulders and dirt onto the strand, which is a popular beach for clothing-optional sunbathers.
