The Federal Highway Administration on Monday said it is investigating the state's response to broken steel seismic safety rods on the San Francisco-Oakland Bay Bridge.
FHWA spokesman Doug Hecox said the agency has launched its review after it received a request by state bridge officials, but it did not have an idea of how long the probe would take.
The agency will examine the California Department of Transportation's conclusion about the cause of the rod failure and the state's recommended fix.
``Public confidence is extremely important, and the public will be confident when we can say backed by independent review that the bridge is 100-percent safe,'' Andrew Gordon, the Bay Bridge project's spokesman, said.
Meanwhile in Sacramento, state Sen. Mark DeSaulnier is holding hearings where he plans to ask Caltrans how the agency could build a bridge with broken partsy.
"This is 10 years later and $5.3 billion over budget and we don't know yet what we got for that $6.3 billion," he said. He said he'd like to hold someone accountable for these problems.
The repair work has put the span's scheduled Labor Day opening in doubt, and Caltrans asked the FHWA to conduct a review to help determine whether the bridge will still open on time.
Bridge officials on Wednesday requested that the FHWA review its findings that the rods broke because hydrogen had penetrated the steel, which caused it to become too brittle.
The failed rods were made in 2008 and were designed to connect the bridge deck to so-called ``shear keys,'' which help control movement during an earthquake.
Officials still do not know how the hydrogen got there, but a metallurgists' report determined the steel used in manufacturing the rods was ``less than ideal.''
The report said the hydrogen corrosion in the rods could have been discovered earlier if Caltrans had required tougher tests. The agency said it is developing new requirements that would require tougher testing in the future.
To fix the problem, Caltrans and the oversight committee are recommending that two steel saddles be installed to hold the shear key's base plate in place. The saddles would be held down by hundreds of steel cables.
Bridge officials hope the FHWA's review into their diagnosis of the problem and their chosen repair option will help provide clarity.
Hecox said the agency did not yet know whether investigators would travel to the site or conduct the probe remotely.
``We believe that resolution of these questions will determine the schedule for opening the new span,'' the Toll Bridge Program Oversight Committee, which oversees the bridge project, wrote in its request.
NBC Bay Area's Jean Elle contributed to this report.