Record rainfall triggered flash floods in Death Valley National Park that swept away cars, closed all roads and stranded hundreds of visitors and workers.
There were no immediate reports of injuries but roughly 60 vehicles were buried in mud and debris and about 500 visitors and 500 park workers were stuck inside the park, officials said.
The park near the California-Nevada state line received 1.46in of rain in the Furnace Creek area.
That is about 75% of what the area typically gets in a year and more than has ever been recorded for the entire month of August.
Since 1936, the only single day with more rain was April 15 1988, when 1.47in fell, park officials said.
“Entire trees and boulders were washing down,” said John Sirlin, a photographer for an Arizona-based adventure company who witnessed the flooding as he perched on a hillside boulder where he was trying to take pictures of lightning as the storm approached.
“The noise from some of the rocks coming down the mountain was just incredible,” he said.
The storm followed another major flooding event earlier this week at the park 120 miles north-east of Las Vegas.
Some roads were closed on Monday after they were inundated with mud and debris from flash floods that also hit western Nevada and northern Arizona hard.
Friday’s rain started at around 2am local time, according to Mr Sirlin, who lives in Chandler, Arizona, and has been visiting the park since 2016.
“It was more extreme than anything I’ve seen there,” said Mr Sirlin, the lead guide for Incredible Weather Adventures who started chasing storms in Minnesota and the high plains in the 1990s.
“A lot of washes were flowing several feet deep. There are rocks probably three or four feet covering the road,” he said.
Mr Sirlin said it took him about six hours to drive about 35 miles out of the park from near The Inn at Death Valley.
“There were at least two dozen cars that got smashed and stuck in there,” he said, adding that he did not see anyone injured “or any high water rescues”.
During Friday’s rainstorms, the “flood waters pushed dumpster containers into parked cars, which caused cars to collide into one another. Additionally, many facilities are flooded including hotel rooms and business offices”, the park statement said.
A water system that provides for park residents and offices also failed after a line broke that was being repaired, the statement said.