Police are investigating the death of a person at the Burning Man festival in Nevada after heavy rains left the site mired in mud, stranding thousands of attendees.

There is no further information on the cause of the death at this time, the Pershing County Sheriff’s Office said in a statement. The incident occurred during a “rain event” that forced local officials to close the entrance and airports to Black Rock City, in the northwestern Nevada desert, where the event is held.

As much as 0.8 inch of rain fell on Friday night. There was an afternoon drizzle Sunday, with a “slight chance” of showers and thunderstorms into the evening, organizers said.

Organizers say they plan to reopen roads for people to leave on Monday as conditions are “improving,” adding that a decision will be made at 9 a.m. The festival’s grand finale will be postponed to Monday night.

“The Burning Man organization’s advice is for participants to delay their departures to avoid getting stuck in the mud, but people are free to leave should they choose to do so,” according to the website.

Attendees had earlier been asked to take shelter and conserve food, water and fuel. More than 70,000 people typically descend on Black Rock City each year for the week-long event. Organizers had deployed mobile cell trailers as well as sent buses to Gerlach, adjacent to Black Rock Desert, to move people to Reno, about 100 miles (161 km) away.

Meanwhile, a White House official said President Joe Biden has been briefed on the situation and the administration is in touch with state and local officials. In brief comments to reporters near his home in Delaware, Biden urged everyone affected to heed the advice of local officials.

From humble origins — having started life as an informal gathering in 1986 in San Francisco — Burning Man has gathered a monied, celebrity following in recent years. Some of this year’s attendees include the musician Diplo, who posted on social media platform X that he walked 5 miles in the mud to escape the venue.

The kick off to this year’s event was disrupted when a group of protesters blocked the highway to the festival, demanding that organizers ban private jets, single use plastics and unlimited power use at the event. Four activists were arrested.

Read more: Protesters Call For Ban on Private Jets, Plastics at Burning Man

--With assistance from Virginia Van Natta and Stephanie Lai.

(Updates with plan to reopen roads Monday in fourth paragraph)