SAN FRANCISCO (AP) - Authorities on Tuesday indefinitely closed the San Francisco-Oakland Bay Bridge after a rod and a metal brace erected last month during an emergency repair job fell onto the bridge's westbound lanes, startling a pair of drivers who collided with the debris and leaving hundreds of others stranded in their cars during the evening commute.
The bridge will remain closed "until further notice" while engineers evaluate the damage and figure out how to fix it, the California Department of Transportation said in a statement. No injuries were reported.
The rod, part of the emergency repair performed on Labor Day, was holding in place a saddle-like cap that was installed over a cracked link. On Tuesday, it apparently snapped, bringing down with it a steel patch roughly 3 feet long at about 5:30 p.m., said California Highway Patrol Officer Peter Van Eckhardt.
"If you look at the totality of the circumstances - you've got the 5:30 commute, you have a 5,000-pound piece of steel falling out of the sky. We are so fortunate that no one was injured or killed," CHP Sgt. Trent Cross told KTVU-TV.
Officers managed to clear the Oakland-bound traffic from the lower deck of the bridge by 8 p.m. but were still clearing cars from the few remaining open lanes of the upper deck an hour later, he said.
The crack was discovered over the Labor Day weekend while long-planned earthquake safety upgrades were being made to the 73-year-old bridge, a California landmark that carries about 260,000 vehicles a day. The bridge had been closed for the long holiday weekend, and state transportation officials initially feared the crack would prevent them from reopening in time for the start of the work week. But the unexpected work only ended up taking a few extra hours.
California Department of Transportation, or Caltrans, officials had nothing to say Tuesday about what might have caused the repair job to fail. The department issued a brief statement saying only that "structural engineers and inspectors are onsite to assess the damage and will make a determination as to how long repairs will take.
"At this time, the bridge is closed until further notice," the statement said.
Abolhassan Astaneh-Asl, a civil engineering professor at the University of California, Berkeley who has spent 20 years studying the Bay Bridge, called the initial crack a "warning sign" of potentially bigger safety issues with the bridge.
"The repair they were doing was really a Band-Aid," said Astaneh-Asl, who criticized Caltrans at the time for rushing to reopen the bridge. "The Band-Aid broke, in essence."
Astaneh-Asl said the failure of the repair job demonstrates the need for a longer-term solution. The span's age and design make it susceptible to collapse, especially if commercial tractor-trailers are allowed to continue using it, he said.
"I think Caltrans is putting public relations ahead of public safety," he said.
Van Eckhardt said at least two vehicles - a car and a small truck - either were struck by or ran into the fallen rod. The driver of the car was shaken up but refused medical attention, he said.
The closure of the bridge was expected to cause a traffic nightmare during the morning commute. The California Highway Patrol was alerting Bay Area transit operators about the closure so they could try to prepare for a crush of additional passengers Wednesday.
A spokesman for the Bay Area Rapid Transit District said the district would be bringing in extra trains and train operators for the morning commute. Caltrans said toll booths at other Bay Area bridges would be fully staffed to accommodate extra traffic.