Contractors knew as early as 1999 that there were problems with some of the bolts attaching massive concrete panels to the ceiling of the Big Dig highway tunnel where a woman was crushed by 12 tons of falling concrete, Massachusetts' attorney general said.
That fall, five bolts in the Interstate 90 connector tunnel failed during testing, Attorney General Tom Reilly said.
"It was not only identified, but there was a plan to address that problem," he said. "What we're trying to determine right now is was that plan implemented."
Preliminary inspections of the tunnel after the deadly collapse Monday night found at least 60 signs of loose bolts and other potential failures in the tunnel's eastbound lanes, according to Massachusetts Turnpike Authority Chairman Matthew Amorello and Michael Lewis, project director of the Big Dig.
In some places, bolts had started to come out of concrete tunnel ceilings. In others, gaps had developed between the ceilings and metal plates that are part of the bracing that has been used to hold the massive panels aloft.
A spokesman for project manager Bechtel/Parsons Brinckerhoff declined to comment on the attorney general's allegation. Contractor Modern Continental did not immediately respond to a phone call and e-mail.
John Christian, an engineer hired to investigate for the Turnpike Authority, said the bolts used a standard design: Holes were drilled into the tunnel's concrete ceiling and bolts were then inserted, along with pressure-injected epoxy.
He said it was possible that inspectors would find "some generic flaw in the systems that are used for designing these panels."
Increased focus on the bolts came as inspectors began reviewing the city's entire highway system _ even parts that are decades old and not part of the troubled $14.6 billion Big Dig system, the nation's most expensive highway project.
Gov. Mitt Romney has focused criticism on Amorello and threatened legal action to oust him, saying Amorello has been secretive, resisted oversight and refused the share information. The Big Dig has been plagued by leaks, falling concrete and other problems linked to faulty construction and oversight, and the state is seeking millions in compensation from its overseers.
The powerful Boston law firm WilmerHale has agreed to represent the state on a pro bono basis, Romney spokesman Eric Fehrnstrom said Thursday.
Amorello has refused calls for his resignation.
"There's obviously a lot of politics involved," he told reporters earlier.
The connector tunnel's eastbound lanes, meanwhile, are closed indefinitely to ensure motorists' safety and to collect more evidence in a possible criminal investigation of the tunnels' designers and builders.
"What happened Monday was a tragedy," Amorello said. "I'm taking every step to ensure it never happens again."
Avi Mor, of Dr. Mor & Associates, a California-based consulting firm specializing in analysis of construction defects, said if concrete failure was to blame for the collapse of the panel, investigators would likely find pieces of concrete still epoxied to the tie rods.
Reilly said one of the bolts that failed was a "clean break" and there wasn't any concrete attached to it.
Federal investigators are now checking whether companies involved in that area fulfilled their obligations, U.S. Attorney Michael Sullivan said. His office brought the first criminal charges in the trouble-plagued Big Dig project in May against six men who worked for its largest concrete supplier, accusing them of falsifying records to hide the inferior quality of concrete.
"We obviously want to identify any public safety risks ... but also to ensure that what the government paid for _ through tax dollars _ is in fact what was delivered," Sullivan told The Associated Press.
Commuters waited years for the Big Dig to bury the city's antiquated central artery and send traffic underneath downtown. But the accident has raised new concerns about safety.
Cab driver Steve Past, 45, said his passengers have been jittery about the tunnels.
"The drivers aren't so scared, but people sitting in the back seat are scared. Because who knows? Today one piece falls down, tomorrow another piece," he said.
- 193 Transportation