An elevated section of Interstate 10 collapsed Sunday amid heavy rains in the California desert, injuring one driver, stranding many others, and halting travel for thousands by cutting off both directions of a main corridor between Southern California and Arizona.
"Interstate 10 is closed completely and indefinitely," said Terri Kasinga, spokeswoman for the California Department of Transportation.
A bridge for eastbound traffic about 15 feet above a normally dry wash about 50 miles west of the Arizona state gave way and ended up in the flooding water below, the California Highway Patrol said, blocking all traffic headed toward Arizona.
The westbound section of the freeway near the tiny town of Desert Center also closed. The roadway was intact but extremely undermined by flooding and could need just-as-extensive rebuilding, Kasinga said.
No timeframe was given for when either side would reopen as crews were diverted from other projects to examine the site.
"They won't even be able to begin assessing the damage until Monday," Kasinga said.
That means those seeking to travel between California and Arizona would be forced to go hundreds of miles out of their way to Interstate 8 to the south or Interstate 40 to the north.
Busy I-10 is the most direct route between Phoenix and parts of Southern California, including Los Angeles.
Transportation officials recommended travellers on the east side of the collapse use U.S. Highway 95 in Arizona to get to the other freeways, and that in California drivers use state routes 86 and 111 to get to Interstate 8 into Arizona.
One driver had to be rescued from a pickup truck that crashed in the collapse and was taken to a hospital with moderate injuries, the Riverside County Fire Department said. A passenger from the truck was able to get out without help and wasn't hurt.
Hundreds of other cars were stranded immediately after the collapse, but the California Highway Patrol was working to divert them in the other direction off the freeway and it wasn't clear if any remained, Kasinga said.
Pamala Browne, 53, and her daughter were driving from Flagstaff, Arizona to Palm Desert, California when they got stranded when the westbound lanes were shutdown.
"Oh my God, we are so stuck out here," Browne told the Desert Sun newspaper. "There's no end to the cars that are stuck out here."
The rains came amid a second day of showers and thunderstorms in southern and central California that were setting rainfall records in what is usually a dry month.
Rain fell Sunday afternoon in parts of Los Angeles County's mountains, the valley north and inland urban areas to the east. The city also was expected to get a late repeat of Saturday's scattered showers and occasional downpours as remnants of tropical storm Dolores brought warm, muggy conditions northward.
"We have a chance of some more heavy rain in LA County this evening, thunderstorms, lightning, possibly some localized street flooding," said National Weather Service meteorologist Joe Sirard.
The showers forced the Los Angeles Angels' first rainout in 20 years and the San Diego Padres' first rainout since 2006.
Saturday's rainfall broke records in at least 11 locations, including five places that had the most rain ever recorded on any day in July, Sirard said.
July is typically the driest month of the year in Southern California. Because of that, Saturday's 0.36 inch of rain in downtown Los Angeles exceeded the 0.24 inch recorded July 14, 1886, which had been the wettest July day in nearly 130 years.
The record is especially significant, Sirard said, because downtown Los Angeles has the longest recording climate station, dating back to July 1, 1877.
Saturday's storm brought flash floods and power outages and turned Los Angeles County's typically packed coast into empty stretches of sand when the threat of lightning forced authorities to close 70 miles of beaches.
Signs warned beachgoers to avoid storm drain flows into the ocean because of Saturday's sometimes heavy rain. The Los Angeles County Department of Public Health recommends people avoid swimming within 100 yards of a storm drain for 72 hours after heavy rain.
Warnings were also in place for high surf and strong rip currents on all south-facing beaches, including Venice, Santa Monica, Malibu, Zuma, Newport and Huntington, officials said.
Meanwhile, the summer storm has helped firefighters advance on two wildfires that broke out Friday.
Muggy, moist conditions were expected to persist through Monday.