(PERSHING COUNTY, Nev.) — A death has been confirmed at Burning Man after thousands of attendees were left mired in mud from torrential rains and were being advised to conserve food and water as all roads in and out of the desert arts and “self-reliance” festival remained shut off Sunday.

The sprawling event is held each year in what’s known as Black Rock City, in the Black Rock Desert in northwestern Nevada. Following what authorities described as “unusual weather conditions” that produced heavy rains Friday night and into Saturday, the gate and airport into and out of Black Rock City remain closed, organizers said. No driving is permitted at the site except for emergency vehicles.

One person has died at the festival, the Pershing County Sheriff’s Office confirmed in a statement Sunday morning.

“The Pershing County Sheriff’s Office is currently investigating a death which occurred during this rain event. The family has been notified and the death is under investigation. As this death is still under investigation, there is no further information available at this time,” according to the sheriff’s office statement.

News of the death came a day after organizers issued an alarming statement to festival attendees.

“If you are in BRC, conserve food, water, and fuel, and shelter in a warm, safe space,” organizers said in a statement posted on X.

President Joe Biden was briefed on the flooding that has stranded thousands of Burning Man attendees, a White House official said Sunday.

“Administration officials are monitoring the situation and are in touch with state and local officials,” the official added. “Event attendees should listen to state and local officials, and event organizers.”

An estimated 75,000 people attended the annual gathering in 2022, and organizers said they expected as many this year. The festival began on Aug. 28 and is scheduled to run through Monday.

Organizers started urging attendees to shelter in place and secure their camps late Friday, as adverse weather conditions moved through the area.

Photos from Burning Man on Saturday showed muddy, wet conditions at Black Rock City and abandoned vehicles in intersections. More rain is possible through Sunday.

Among those attending this year’s event were Diplo and Chris Rock, who both reportedly fled on foot. The DJ said on X Saturday that he and the comedian walked five miles in the mud to get out of Burning Man before they were picked up by a fan.

Access to Black Rock City will remain closed for the remainder of the event, organizers said, while urging people not to travel to the site.

The Bureau of Land Management and the Pershing County Sheriff’s Office decided to close the entrance to Burning Man for the remainder of the event due to the rainfall, Pershing County Sheriff Jerry Allen said in a statement Saturday evening.

Allen said in a statement that the several hours of heavy rain “made it virtually impossible for motorized vehicles to traverse.”

The sheriff said some vehicles have “caused damage to the Playa surface.”

On Sunday night, festival organizers said the roads were expected to open Monday for attendees to leave the area.

Significant flooding has been occurring in Las Vegas and surrounding areas as monsoonal rains and storms inundate the Southwest.

The Las Vegas Fire Department confirmed Sunday that one person was found dead in the flooding early Saturday west of downtown Las Vegas. “Upon arrival, a person was found unconscious and unresponsive. It is believed the person is a drowning victim,” the fire department said in a statement, adding that the Las Vegas Metro Police Department and the Clark County Coroner were investigating the death.

Flood watches remain in effect for cities such as Las Vegas and Flagstaff, Arizona through Sunday night. The heavy rain and flash flood potential will then shift northward into northern Utah and southeastern Idaho on Sunday.

Allen said more bad weather is in the forecast for the Black Rock City area, which is about 122 miles from Reno.

“There is more rain forecast for the next few days, which could cause further delays and disruptions for participants attempting to leave the Festival as well as other operations within the Festival,” Allen said.

The sheriff said additional resources have been collected from around Northern Nevada to “assist with providing people with medical needs on the Playa until people can do it on their own.”

ABC News’ Marilyn Heck contributed to this story.

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