Crews worked around the clock to repair the San Francisco-Oakland Bay Bridge, but officials still had no firm idea Saturday of when the span would open to traffic.

The bridge will remain closed at least through early Saturday evening while crews continue cutting and grinding parts so they don't rub together, State Transportation Department spokeswoman Lauren Wonder said.

"Crews are working 24-7 to get these repairs as quickly and efficiently but as safely as possible," Wonder said.

She could not say when the bridge would reopen or if Monday morning commuters would be faced with another grueling commute around a closed bridge.

Work began Tuesday night after two rods and a crossbar installed over Labor Day weekend to repair a crack failed, sending 5,000 pounds of metal into rush hour traffic. One person sustained minor injuries.

Wonder said crews on Saturday were installing the new rods, a tedious process that requires workers to put the metal rods in place and then uninstall them while adjustments are made to ensure they don't rub against other metal parts.

Once the rods are cut and ground to a perfect fit, testing could begin Saturday afternoon, Wonder said. That process takes about three hours, on top of the time independent inspectors might need to check out the repair work.

"We want to make sure this is safe and works correctly," Wonder said.

The Bay Area Rapid Transit system, which links Oakland and San Francisco through a tube beneath the Bay, planned to run trains overnight if the bridge remained closed.

Caltrans has not released a cost estimate for the emergency repairs.