DESCANSO, Calif. — A woman died and a teen hiker suffered serious injuries in a fall Thursday at a popular backcountry hiking trail in East County, authorities said.

The fall was reported just before 10 a.m. at Three Sisters Falls in the unincorporated area of Descanso, Lt. Jeff Ford with the San Diego County Sheriff’s Department (SDSO) said in a news release.

Authorities learned a group — a woman and four teenagers — were hiking along the ledge of one of the falls when one of the teens slipped.

“The woman supervising the teenagers attempted to keep the girl from going over the ledge,” Ford said.

However, both the woman and girl suffered serious injuries in the fall, according to law enforcement. The woman died at the scene while the teenager was taken to a hospital via helicopter with serious but non-life-threatening injuries.

The name of the deceased is currently being withheld pending notification from the family, per SDSO.

There is no suspicious activity connected to the fall, as the sheriff’s department confirmed it was “just a terrible accident.”

The 4.5 mile-roundtrip trail was the site of a helicopter rescue last month when a 61-year-old hiker suffered an ankle injury. Other helicopter rescues have been reported at Three Sisters Falls throughout the years.