Sept. 3 (UPI) — Roads into and out of the Burning Man music and culture festival in northern Nevada remained closed early on Sunday amid continued heavy rainfall, stranding tens of thousands of attendees.

Rains that began falling in Black Rock City, Nev., on Friday transformed the Burning Man playa, which typically is a hard desert surface, into a sea of mud, making travel for the 73,000 festivalgoers nearly impossible.

The precipitation continued Sunday and as National Weather Service in Reno placed portions of the area under a “marginal risk” of isolated severe thunderstorms, including heavy rains, frequent lightning, gusty winds and hail to 1-inch diameter.

The Pershing County, Nev., Sheriff’s Office and the Bureau of Land Management closed the entrance to Burning Man for the remainder of the event.

“Please avoid traveling to the area; you will be turned around. All event access is closed,” the sheriff’s office warned Saturday.

Event organizers advised festivalgoers to “shelter in place” and prohibited all vehicles from driving into the muddy playa.

In a update issued late Saturday, the organizers insisted “we are all well-prepared for a weather event like this” although the festival’s signature event — the burning of the “Man” effigy — was postponed.

They said mobile cell trailers were being deployed to “strategic positions” and that Internet service would be available “sometime Saturday evening.”

Organizers also indicated buses were being provided to take attendees who chose to walk off the playa to Reno, although they were advised to check recommendations on “when walking is viable or not.”