Caltrans says there's no estimated time for when the Bay Bridge will reopen and that there's still a lot of work to be done.

Hhigh winds hampered efforts to make quick repairs on the Bay Bridge Wednesday. In a late afternoon news conference spokesman Bart Ney said drivers should be ready to get to work Thursday without the bridge.

Officials said it is possible that the winds may have been the reason a portion of a construction repair job collapsed Tuesday.

Both directions of the bridge were shut down Wednesday. Caltrans said the repair work could be complete by noon Thursday, but added the work would still need to be inspected before the bridge could be open to drivers.

The pieces that failed were parts of major repairs done last month after state inspectors discovered a crack in an "eyebar," an important structural beam. The rods that broke were holding a saddle-like cap that had been installed to strengthen the cracked eyebar.

Caltrans engineers were trying to figure out why the recent repairs -- which were supposed to last until the new bridge opened in 2013 -- failed in less than two months.

Ney said the strong winds likely played a role in the failure, which heightened concerns by some experts about the integrity of the repair and the bridge's safety in an earthquake. Scientists in 2008 said there is a 63 percent probability of a quake similar to the 6.9-magnitude Loma Prieta temblor in the Bay area over the next 30 years.

Miraculously, only three vehicles were hit and nobody was hurt.

"I thought I was going into the Bay," said Andrea Nelson, a marketing consultant and personal coach who saw the crossbar and two rods fall and bounce on the road ahead of her as she headed into San Francisco for dinner. She swerved and her car spun out as she ran over the rods, which gashed her tires.

"I have lost so much confidence in the experts, the millions of dollars that are being spent to reconstruct and build a new bridge," she said. "I just find it shocking and unacceptable."

Abolhassan Astaneh-Asl, a civil engineering professor at the University of California, Berkeley who studied the effects of the 1989 earthquake on the bridge, called the repair last month a "Band-Aid" that jeopardized public safety to get the bridge open quickly.

"When this eyebar fractured, this is very serious element of this part of the bridge. So the safety issue is very serious here," he said. "The repair done, in my opinion, is very unusual to put it mildly."

The main contractor on the repairs, C.C. Meyers, Inc., stood by the work, but deferred to Caltrans to determine why the pieces failed, spokeswoman Beth Ruyak said.

The parts to repair the span arrived overnight Tuesday but crews couldn't begin the work until winds died down. Ney said the winds "are drastically slowing down our progress" as workers put new pieces of steel in place.

The Federal Highway Administration sent engineers to investigate what caused the repairs to fail. "That's the primary task at hand," said Nancy Singer, a spokeswoman for the highway administration. The agency said it had not inspected the Labor Day weekend repairs.

The closure has had a ripple effect on traffic throughout the Bay Area. Some 280,000 drivers use the span daily.

Drivers on the upper deck of the Bay Bridge got the shock of their lives around 5:30 p.m. when a large cable and a piece of heavy metal came flinging toward them.

A box-type truck was hit with the cable. The driver says he slammed on his brakes in order to keep from hitting the chunk of metal at the end of the cable. The cable landed on his roof after shattering the man's windshield. It also landed in at least two lanes of traffic. The 5,000 pound piece of metal swiped another car on its way down, peeling back the hood like a sardine can. The couple inside that car had just started a vacation after flying to the Bay Area from Canada.

It's not clear what brought the cable and the chunk of metal down, but the winds had been heavy all Tuesday. Caltrans had a high wind alert for Bay Area bridges throughout the day.

Commenting on the failure, Ney said, "we're deeply sorry about the incident and the damage to the property owners and the delays for commuters."