As thousands of people remain unable to leave the Burning Man festival in the Nevada desert after heavy rains inundated their campsites with ankle-deep mud Saturday, authorities say they are investigating a death at the event.

Attendees were told to shelter in place in the Black Rock Desert and conserve food, water and fuel after a rainstorm swamped the area, forcing officials to halt any entering or leaving of the festival.

The remote area in northwest Nevada was hit with 2 to 3 months worth of rain – up to 0.8 inches – in just 24 hours between Friday and Saturday mornings. The heavy rainfall fell on dry desert grounds, whipping up thick, clay-like mud that festivalgoers say is too difficult to walk or bike through.