From NBC:

A second Burning Man festivalgoer has died, the festival said Saturday. Craigh Mann, 60, was found dead in his camp in Black Rock City, Nevada, at 3 p.m. Saturday, the festival said. No cause of death was disclosed. “Our thoughts and deepest condolences are with the participant’s family, friends, campmates, and all those affected by this loss,” the festival said in a statement. It was the second death at the annual psychedelic, music and art festival in the Nevada desert, which draws a crowd of about 70,000.
From New York Post (tabloid):
A man was found dead at the Burning Man festival in the Nevada desert, organizers revealed.
He was taken to the camp’s emergency care center and pronounced dead. The death comes as rain forced the closure of the festival’s main entry and exit gate in the Black Rock Desert.