Record rainfall drenched the driest city in North America on Tuesday afternoon, stranding cars, swamping the county courthouse lobby and delaying flights out of McCarran International Airport.
Several major roads were closed by the downpour, including portions of the Las Vegas Beltway.
The Beltway was shut down at Interstate 15 in the southern part of the valley. Charleston Boulevard was closed in both directions east of I-15.
The Clark County Fire Department rescued more than 50 people from their vehicles. It responded to about 40 swift-water rescue calls, almost all involving drivers stranded in floodwaters.
No injuries were reported.
Las Vegas police reported flooding at several intersections: Pollock Drive at Warm Springs Road, Swenson Street and Twain Avenue, and Charleston and Eastern Avenue.
The rain also caused problems at the Regional Justice Center, which closed to all nonessential business Tuesday afternoon because of flooding in the lobby.
Court marshals said water started gushing from the ceiling above the metal detectors at the main northeast entrance about 1:45 p.m.
"It looked like a waterfall," one marshal said.
The marshals said they shut down the metal detectors and diverted people to the southeast entrance, where they were searched by hand as they entered the 17-story building. There are no metal detectors on that side of the building.
Several security cameras on the north side were knocked out by the flowing water.
As of 3:30 p.m., the marshals said, they didn't know whether the water had damaged the metal detectors at the building's only secure public entrance. Cleanup was under way, and full operations were expected to resume this morning, a court spokeswoman said.
At University of Nevada, Las Vegas, a parking lot near the Thomas & Mack Center filled with several feet of water, submerging some vehicles to the bottoms of their doors or deeper.
A photograph of the lot showed two men floating through the water on inflatable pool chairs.
The National Weather Service received unofficial reports of more than an inch of rain in less than an hour in some valley neighborhoods.
One part of Summerlin was drenched with more than 2 inches over a three-hour span, according to a Clark County Regional Flood Control District rain gauge.
The valley's official weather station at McCarran had logged 1.17 inches of rain by 4:30 p.m. That was enough by itself to set a new record for the date, erasing the old mark of 0.61 from Sept. 11, 1998.
Already this ranks as the sixth-wettest September since 1937, according to National Weather Service records.
Lightning from the storm forced McCarran to halt aircraft fueling operations for about an hour early Tuesday afternoon, and the Federal Aviation Administration would not allow flights to land at the airport for about 30 minutes because of the weather.
The delays moved from the air to the ground later in the day, as flooding closed roads and slowed traffic around McCarran. Airport spokeswoman Linda Healey advised travelers to check their flight status before going to the airport and to allow for more time to get there.
The Fire Department went door to door in a southeast valley neighborhood Tuesday night, asking residents to leave their homes because flooding may have damaged their electrical systems.
The warning covered 45 homes near Walton Heath Avenue and Moortown Street, east of Nellis Boulevard and south of Sahara. Firefighters were concerned about the possibility of electrical fires.
Review-Journal writer Jeff German contributed to this report. Contact reporter Henry Brean at firstname.lastname@example.org or 702-383-0350. Contact reporter Mike Blasky at email@example.com or 702-383-0283.