MALIBU (CBSLA) — A night of surfing in Malibu turned tragic for two brothers.

At about 11:40 p.m. Thursday, screaming was reported at Topanga State Beach, where sheriff’s deputies found a man who had been performing CPR on his brother. The two brothers had been out in the water for a night session of surfing.

As they surfed, the brothers lost track of each other, authorities said. One of them later found his brother face down in the water and dragged him to shore, where he performed CPR, but was not able to save him.

Sheriff’s deputies say the two brothers are skilled surfers in good physical shape. The brother who died had been a pro surfer at one point, according to a deputy.

The surfer’s father and brother were both on the scene immediately after his death.

The surfer was later identified as Damon Michael Geller, 48, of Pacific Palisades, according to the coroner’s office and the Los Angeles County Sheriff’s Department.

A high surf advisory has been in effect for Southern California’s beaches since Monday after being extended multiple times. Earlier in the week, the high waves had damaged the Ventura Pier.

High surf is expected through noon on Friday. Surf heights for the Central Coast are expected between 10 and 16 feet, and VTU/LA Coasts expected between 5 and 9 feet. Some of the impacts include dangerous rip currents and beach erosion. #SoCal #LAweather #CAwx pic.twitter.com/MDqUkGlO54 — NWS Los Angeles (@NWSLosAngeles) December 21, 2018

It’s not clear if the high surf advisory, or a possible medical emergency, played a role in the surfer’s death. An autopsy is pending to determine Geller’s cause of death.

The tragedy was first reported to 911 as reports of someone screaming on the beach by people in a nearby Arco gas station, but Los Angeles County sheriff’s deputies are not calling the death suspicious.