San Francisco , California ( CNN ) -- Repair work on the San Francisco-Oakland Bay Bridge will continue nonstop into the weekend and the bridge may reopen Monday , but officials were making no promises Friday . `` Commuters are going to need to check back with us over the weekend , '' said Bart Ney , a spokesman for the California Department of Transportation . `` We 're going to do everything we can to get the bridge open for the Monday morning commute , but safety is the priority for us right now . '' Repair work has not stopped since it began Tuesday night when two steel rods and a steel crossbeam plummeted from the bridge , landing on the roadway and forcing the span 's closure . The same section had been the site of repairs over Labor Day weekend , when crews fixed a crack . On Friday , workers were grinding the areas where there was the potential for steel-on-steel connection , Ney said . `` We want them to be very smooth . '' The rods ' alignment has not been completed to the point where workers could begin stressing them , he said . Once that work is complete , a third-party group will look at how the system handles vibrations , he said , adding , `` There is still a lot of work to be done . '' Transportation officials had said Thursday night that repairs of the bridge , which carried about 280,000 vehicles per day , would be complete by late Friday morning , but Ney said contractors were still working on custom-fitting steel for the structure . Crews worked Friday to replace four steel rods . One of those had failed and caused the problems , Dale Bonner , California 's secretary of business , transportation and housing told reporters Thursday . Engineers also will make sure the rods are centered and will strengthen the welds to ensure stability , Bonner said . Vibrations in the rods , affected by strong winds , caused the break , officials said . In the wake of the bridge 's closing , commuters flocked to the Bay Area 's rail system . On Thursday , Bay Area Rapid Transit ( BART ) said , the system carried the most passengers ever , breaking a record set the day before . About 442,000 people took BART , 24 percent more than on an average Thursday , the agency said in a news release .
News : ` ` We 're going to do everything we can to get the bridge open '' Monday . Pieces of debris from bridge fell onto roadway on Tuesday , forcing closure . Century - old bridge spans San Francisco Bay , carries about 280,000 vehicles daily . It has been popular with riders since Bay Bridge closure .