(KTLA) -- A woman died after a bluff collapsed at Grandview Surf Beach in Encinitas Friday afternoon, authorities said.
Discarded beach chairs and sun hats could be seen near the portion of cliff that officials say sloughed off around 3 p.m. beneath a staircase giving access from the 1700 block of Neptune Avenue.
In addition to the fatality, four others were hurt.
Two people were in critical condition, one of whom had to be airlifted for treatment, according to Encinitas Fire Chief Mike Stein.
Another two people suffered minor injuries. One of them was treated and released at the scene, while the other was taken to a hospital, Stein said.
No identifying information was immediately available on the victims, other than that the person killed was a woman. Authorities were unsure if they were local to the area or visiting, according to FOX40's sister station, KTLA.
Search efforts were still underway in one portion of the collapsed debris that authorities hadn’t been able to comb through completely due to instability. Cadaver dogs were brought in to search that area, Stein said.
Earlier, San Diego County Sheriff’s Lt. Ted Greenawald told the San Diego Union-Tribune that first responders were working to rescue two others believed to be trapped. It was unclear if those people were later accounted for.
A man who lives in the area told KTLA's sister station KSWB in San Diego that he was working from home when he heard the commotion outside.
The resident, who gave his name as Jim, said there were children and about a dozen adults in the group the bluff collapsed onto, and it appeared as if it could have been a family gathering.
Jim said he saw rescue crews pull out a woman trapped underneath some “pretty big-sized boulders.”
Efforts were underway to stabilize the cliffside as much as possible. Authorities were concerned about the possibility of a secondary collapse with portions of the bluff behind the part that sloughed off still unstable.
However, Stein said an engineer had assessed the area and determined homes along Neptune Avenue are far enough back to not be in danger.
Officials say the spot wasn’t previously known to be unstable.
The collapsed portion was estimated to contain 15 to 20 cubic yards of material stacked about 10 feet high, according to Stein.
A page on the Encinitas city website says failures are a "frequent" occurrence with the area's sandstone bluffs, and visitors are advised to avoid sitting or standing beneath them. Walking on top of them is also prohibited in most areas.
“This is a naturally occurring event. All of these bluffs have water seepage,” said Brian Ketterer with California State Parks. “It’s sandstone that sits on other soils, and then sandstone again.”
Lifeguards try to keep people about 25 to 40 feet away from the cliffside, and there are signs on most beaches warning beachgoers of the danger, Ketterer said.
It was unclear whether such a sign was posted near the site of Friday’s collapse.
A portion of the coastline would be closed, from the Ponto Beach area to several hundred yards south of the Grandview Beach access, for at least the remainder of the day.