Burning Man attendees are expected to begin leaving the festival on Monday after a downpour and massive flooding left them stranded over the weekend.

The festival, held in the Black Rock Desert in northwestern Nevada, garnered more than 70,000 people last year, and just as many were expected this year. Burning Man began on Aug. 28 and was scheduled to run through Sept. 4.

One person died at the festival amid the unusual weather conditions, the Pershing County Sheriff's Office confirmed Sunday morning in a statement. The death is under investigation.

"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.

Organizers are expected to open the gate at the venue so attendees can begin to depart on Monday morning. They are, however, recommending that people delay their departures to avoid getting stuck in the mud.

What happened?

Black Rock Desert was faced with two to three months worth of rain in just a matter of hours on Friday, Sept. 1.

On average, the area gets only 0.2 inches of rain or less in September -- but festivalgoers were met with up to 1 inch in some areas, in a desert that gets only about 5 to 6 inches of rain per year.

This is typically the driest time of the year for the desert, and it does not take much rain to make the desert floor a mud bath.

The downpour was followed by cooler temperatures and cloudy skies -- extending the drying out process.

However, better conditions on Monday are expected to bring "a welcome chance to dry out," event organizers said.

What did festivalgoers face?

In response to the unusual weather, event organizers shut down traffic in or out of what is called Black Rock City -- where the festival is held in the desert -- including the local airport.

Photos show festival grounds covered in muddy puddles, with some attendees braving the messy conditions.

DJ Diplo claimed on X, formerly known as Twitter, that he and Chris Rock walked 5 miles in the mud before a fan picked them up.

Attendees were asked to shelter in place, conserve food and water and avoid driving or operating any vehicle on the campgrounds.

Attendees were advised not to operate any generators or other electrical instruments standing in water.

On Sunday, an afternoon drizzle compounded onto already poor conditions at the campgrounds. The main gate road was still impassable on Sunday night, and alternative exit routes have been planned for the expected exodus of attendees from festival grounds on Monday.

As some attendees prepare to leave on foot, shuttle buses are running to assist in the exit. It is unclear when roads might be dry enough for RVs and vehicles to navigate the roads safely, according to organizers.

Updates are being housed on the "2023 Wet Playa Survival Guide" created by event organizers.

"Burning Man is a community of people who are prepared to support one another," the guide read. "We have come here knowing this is a place where we bring everything we need to survive. It is because of this that we are all well-prepared for a weather event like this."

Organizers said they worked with "agency collaborators on the local, county, state, tribal, and federal levels" to prepare and coordinate response to the weather conditions.

On Sunday, mobile cell trailers to boost cell service and charging stations were placed around the festival grounds amid the recovery efforts, according to organizers.

Burning Man has been hosted for over 30 years, according to a statement from the organizers.

In 2013, according to a blog post in the "Burning Man Journal," a rainstorm similarly rolled in, unexpectedly "trapping 160 people on the playa overnight."

On Sunday, President Joe Biden said he was in contact with locals and that the government "ought to be getting everybody out of there."

"We're in contact with the local people," Biden told reporters.

The White House recommended that event attendees "listen to state and local officials, and event organizers."