OAKLAND — The Bay Bridge’s broken bolts have busted the schedule, forcing the construction team to postpone for weeks or months the opening of the Bay Area’s new signature bridge while critics lambast the builders for missteps that contributed to the delay.

Citing a longer than expected timetable to retrofit the seismic stabilizers where key anchor rods snapped in March, the span will not open to traffic immediately the morning after Labor Day as planned. No new opening date has been set.

“Heads should roll,” said Senate Transportation Committee Chairman Mark DeSaulnier, D-“Concord. “It’s unconscionable that people have been exposed to so much risk of an earthquake on the old the bridge and paid so much for the new one. People need to be held accountable on these big projects.”

Bay Area legislators got the bad news during a closed-door meeting in Sacramento on Monday morning with the Toll Bridge Program Oversight Committee, comprised of directors of the Metropolitan Transportation Commission, California Transportation Commission and Caltrans.

The committee also released a scathing report detailing a cascade of missteps and errors that triggered the catastrophic failure of the high-strength bolts and a crisis of public confidence in the $6.4 billion span’s seismic safety.

The oversight committee spread the blame liberally among Caltrans, bridge consulting engineers of record at T.Y. Lin and Moffatt & Nichol, and bridge contractor American Bridge/Fluor Enterprises.

The panel concluded that Caltrans and the consultants inappropriately applied a single industry standard for bolts without factoring the unique purposes and heavy loads required of the Bay Bridge fasteners.

The committee also criticized principle suspension span contractor American Bridge/Fluor Enterprises for allowing water to collect around the shear key bolts that later broke.

The foul-ups eventually led to the need for repairs to the seismic stabilizers in the large pier east of the tower where 32 out of 96 anchor rods snapped after contractors tightened them down.

Those repairs won’t be done until Dec. 10 at an estimated cost of up to $20 million.

To fix the problem and handle the heavy loads originally intended for the steel rods, engineers have designed an exterior saddle and cable system. A saddle will be affixed to the top of the shear key with cables stretched over it and anchored on the outside of the shear key. Then the entire assembly will be encased in concrete.

None of the other fasteners on the bridge show signs of imminent fracture after subsequent testing although some may need to be replaced in coming years.

A new date for opening the span will likely be the topic of considerable debate Wednesday when the oversight committee appears before the Bay Area Toll Authority, the board of county and city elected officials who oversee toll funds.

The committee will “select a bridge opening date based upon actual completion of the east pier retrofit work, weather windows, traffic impacts and other information as it becomes available,” according to a published statement.

The switch to the new span requires a four-day shutdown of the old bridge and Caltrans initially chose Labor Day weekend because traffic volumes are lower.

A post-Dec. 10 opening date puts the possible timetable into the Christmas season when the numbers of commuters on the bridge also declines.

But the shift also means potentially poor construction weather for paving, pouring concrete and lane striping.

Commuters asked Monday about the prospect of more delay expressed disappointment but preferred safety over speed.

“Safety first,” said Dupriest Hill, who works in Oakland. “I think we should get it right. I would hate for a travesty to happen, like a failure of the bridge.”

The open vs. close question once again pits engineers’ predictions of an even more disastrous collapse of the 1936 span in the next temblor against public fears about the safety of a new bridge on the technological edge.

Some experts say any delay is dangerous. Waiting for the shear key retrofit is unnecessary, according to renowned experts including Frieder Seible, chairman of the Toll Bridge Program Seismic Safety Peer Review Panel.

The bridge doesn’t need the shear keys except during an earthquake and the old 77-year-old span’s extraordinary earthquake vulnerability outweighs the “minuscule” risk that the new span would weaken or fail without fully functioning shear keys, Seible said.

“The likelihood that a big earthquake will come between now and the time that the bolts are fixed is a very small exposure window when compared to the 150-year life span of the bridge,” Seible said. “It is a risk worth taking compared to keeping traffic on the old bridge.”

The opening day dilemma is the latest nail-biter in a suspense story that began 24 years ago. That’s when the Loma Prieta earthquake shook loose a 250-ton piece of the Bay Bridge’s upper deck and killed a motorist, one of 63 people who lost their lives in the shaker.

Bay Area residents ultimately demanded a safer, albeit iconic, bridge.

After years of bickering over the design and who would pay the fivefold cost overruns, the $6.4 billion span was on the verge of opening.

The modern 2-mile bridge is actually two spans — a reinforced concrete box girder viaduct and the world’s largest single-tower self-anchored suspension span — linked to Oakland and Yerba Buena Island via complex transition structures.

The 2013 bridge is packed with seismic and construction innovations, many of them unprecedented at this scope and size, and tested only in laboratories.

Yet, nearly every engineer who has studied the existing 77-year-old bridge predicts it will suffer a catastrophic and possibly deadly failure when the next big temblor strikes the adjacent Hayward or San Andreas faults.

“The evidence is convincing that the new bridge is many, many times safer than the proven vulnerable old bridge,” said Metropolitan Transportation Commission spokesman Randy Rentschler. “So, I don’t have any doubt that we take the earlier opportunity we can to get traffic onto the new span. It is a function of the time it will take to get the retrofit done.”

Reporter Brittny Mejia contributed to this story. Contact Lisa Vorderbrueggen at 925-945-4773, lvorderbrueggen@bayareanewsgroup.com, politicswithlisav.blogspot.com or Twitter.com/lvorderbrueggen.