SAN DIEGO — The hiker who died on an El Capitan trail over the weekend has been publicly identified.

Sergio de Jesus Santiago Sufy, 27, died Sunday evening while hiking the trail in Lakeside with friends, according to the San Diego County Medical Examiner’s Office. While two people went back to their car to get water, Sufy, a Tijuana resident, became unresponsive, the office said.

The hiker had shown heat illness symptoms and collapsed, Lakeside Fire Protection District Battalion Chief Chris Downing added. The group called 911 and followed CPR instructions from the dispatcher, Downing said.

Paramedics found Sufy not breathing and without a pulse, and pronounced him dead at the scene, fire officials said.

The medical examiner’s office have not listed a cause of death.

The San Diego County Sheriff’s Department is investigating.