SAN DIEGO — A bluff collapse on Black’s Beach prompted some closures Friday afternoon, but no one was hurt, authorities said.

San Diego Fire-Rescue Department reported the collapse around 2:45 p.m., asking beachgoers to avoid the area.

No one was injured in the collapse, fire officials said on Twitter.

The La Jolla Trail, located above Black’s Beach, is closed, SDFD said.

Pat Abbott, professor of geology at San Diego State University, called the collapse the most significant failure in 40 years. 

“Was the ocean waves beating on them? Was gravity pulling on them? Now saturated with rainwater at this particular time, was the highest tides in the air going on right now? This place can have landslides, major ones at any time,” Abbott said.

Witnesses say the force of the collapse hit the shore so hard the sand cratered and exploded upward.

FOX 5’s Jaime Chambers contributed to this story.