LOS ANGELES — All traffic along a major freeway connecting California and Arizona was blocked when a bridge over a desert wash collapsed during heavy rain Sunday, and the roadway in the opposite direction suffered severe damage, authorities said.

The collapse on Interstate 10 in southeastern California left one driver injured, stranded numerous motorists and complicated travel for thousands for what officials warned could be a long time.

“Interstate 10 is closed completely and indefinitely,” said Terri Kasinga, spokeswoman for the California Department of Transportation.

The closure will force motorists hundreds of miles out of their way to Interstate 8 to the south or Interstate 40 to the north.

An average of more than 20,000 cars per day pass through the area that is shut down, according to federal highway statistics.

The bridge for eastbound traffic about 15 feet above the wash gave way, the California Highway Patrol said, blocking traffic headed toward Arizona.

One driver of a pickup truck that fell with the freeway had moderate injuries, officials said.