A 38-year-old Newport Beach lifeguard died over the weekend after falling from his bicycle, authorities said Monday.

Brian Gray, a 21-year veteran, fell from his bicycle at about 2 a.m. Saturday in a city parking lot at 26th Street, according to Newport Beach police Sgt. Eric Peterson.

The cause of the accident has not yet been determined.

Gray, who served as a senior seasonal guard, was remembered as a mentor to younger lifeguards and an experienced waterman whose time in the water dated back to playing water polo for Corona del Mar High School, according to Assistant Chief Lifeguard Rob Williams.

"Brian loved the beach and seemed to have lifeguarding in his blood," according to an internal city memo.

Gray lived on the Balboa Peninsula and grew up in Corona del Mar. He was a "mainstay" in the department's CPR schools program, according to the memo.

Gray was remembered in part for his quick thinking and "tireless efforts" in digging out a young boy entrapped in the sand in July 2006 for which he received a bravery award from the American Red Cross.

Most recently, Gray worked as a courier for the Newport Beach Fire Department.

Gray attended Harbor View Elementary School and CdM High.

Plans for Gray's memorial are still being determined, but the service will likely be in early January, Williams said.

"It's been a tough few days around here with the passing of [retired lifeguard] Buddy Belshe and Brian Gray … especially with the holidays," Williams said. "It just reminds everybody to enjoy your life a little more and keep the people you love close to you."

Even after his death, Williams said Gray continued to save lives by donating his organs.

"In his true character he still continued to help others," Williams said.

He is survived by both of his parents John and Mary Lou, his brother Robert, sister-in-law Claire, nieces Nya and Gorgie and his nephew James.

lauren.williams@latimes.com

Twitter: @lawilliams30