A portion of Sunset Cliffs collapsed Wednesday in an area already cordoned off in preparation for the erosion.
At about 5 p.m., a witness saw dirt falling from the cliffside at 1303 Sunset Cliffs Boulevard, according to San Diego Fire-Rescue officials.
No one was in the immediate area when it came down.
About a month ago, a geologist visited the portion of cliff and recommended officials barricade the area because a collapse was imminent.
A piece of yellow caution tape warned people not to walk along the stretch. The barricade is still in place.
In January, SDSD geology professor Pat Abbott told NBC 7 a large crack that had formed in the rock was due to gravity, the cliff's steepness and tides. El Nino rains were the "straw that broke the camel's back," he said.
