One person has died at the popular Burning Man festival in the Nevada desert as thousands remain trapped after heavy rains flooded the area and created ankle-deep mud.

The remote area in northwestern Nevada was hit by heavy rain over a 24-hour period, between Friday and Saturday morning. Heavy rain fell on dry desert terrain, creating thick clay-like mud, with those in attendance saying it was very difficult to walk or cycle through.

Those present were told to flee to the Black Rock Desert and conserve food, water and fuel. At the same time, the Authorities stopped any entry or exit from the festival.

More rain is likely Sunday afternoon, according to a forecast from the National Weather Service’s Reno office. “The strongest storms will be capable of very heavy rainfall, small hail and wind gusts up to 40+ mph,” the weather service noted.

The Pershing County Sheriff’s Office said it was investigating “a fatality that occurred during the rainfall.” Authorities have not publicly named the person or given details about the circumstances of the death.

“The family has been notified and the death is under investigation,” the sheriff’s office said in a news release late Saturday.

Authorities have not given any information on when the roads could be reopened, but sunshine is expected to return on Monday.

For now, the gate and airport at Black Rock City remain closed and no driving in or out of the city is allowed, except for emergency vehicles, organizers said on social media.

Vehicles trying to leave the site will get stuck in the mud, Burning Man organizers said Saturday, warning that travel is and will remain difficult.