Wide risk, wide blame

WASHINGTON -- Federal investigators blamed multiple Big Dig contractors and the Massachusetts Turnpike Authority yesterday for last summer's fatal tunnel collapse, concluding that the wrong kind of glue was used to hold up part of the concrete ceiling and that project oversight was inadequate to detect the problem.

Because the glue was too weak to support the multiton ceiling panels, the investigators said, several other sections of the ceiling were "at imminent risk of failure" at the time of the accident.

In a four-hour hearing and a summary report that named those responsible, the National Transportation Safety Board spared no party.

Much of the blame rests with the ceiling designer, Gannett Fleming Inc., for not specifying the use of epoxy strong enough to keep bolts from gradually coming loose, the board said. But it also found substantial mistakes by the Massachusetts Turnpike Authority and by other contractors. Their failure to catch the error and to aggressively investigate when bolts started coming loose during construction, contributed to the tragedy, the board found.

The board primarily faulted the use of a fast-drying form of epoxy that was unable to hold up the ceiling for a long period without the bolts creeping out. After the collapse, investigators found that a significant number of the bolts used to support the ceiling in the easternmost 200 feet of the Interstate 90 connector tunnel had partially slipped out.

"Over time, the epoxy deformed and fractured" until several ceiling supports pulled out, said the report.

The result was that late on the night of July 10, 2006, 26 tons of concrete and steel crashed down on a Buick headed for Logan International Airport, killing 38-year-old Milena Del Valle of Jamaica Plain and fundamentally shaking the city's trust in the safety of the Big Dig tunnels.

Del Valle's 24-year-old daugh ter, Raquel Ibarra Mora, traveled from Costa Rica to attend the meeting in Washington and a memorial service for her mother last night in Boston.

"I have mixed emotions," she said through a translator. "It was a very difficult day. I wished the report could have been released on a day other than the anniversary. I have to relive, through the findings, what actually happened. But I'm very pleased with the NTSB because the NTSB seemed to have done a thorough job and to have found the people responsible for this act."

Gannett Fleming and Bechtel/Parsons Brinckerhoff, the consultant hired to manage the overall design and construction of the $15 billion highway project, failed to recognize long-term bolt slippage as a potential problem that needed to be taken into account in the design and approval process for the tunnel ceiling, the board found. It said the supplier of the epoxy bolts, Powers Fasteners Inc., provided "inadequate and misleading" information about its epoxy and the company then failed to determine that the wrong glue had been used when bolts started coming loose during construction.

Subsequently, Bechtel/Parsons Brinckerhoff and Modern Continental Construction Co., the tunnel builder, failed to monitor whether bolts continued to come loose, and the Turnpike Authority did not inspect the ceiling after the tunnel opened in 2003.

"There are plenty of issues to go around for everyone," Mark V. Rosenker, the safety board's chairman, said at the conclusion of the hearing.

The board called for a nationwide moratorium on the overhead use of epoxy bolts in highway construction if their failure would endanger the public. It recommended that the Federal Highway Administration develop national standards for testing epoxy bolts used in this way -- none now exist -- and urged all states to identify locations where overhead anchor bolts are used and inspect them.

Using epoxy bolts to hold up objects overhead "appears . . . to introduce voids into the adhesive that can reduce" the weight- bearing capacity and reliability of the bolts, the report said. The safety board also called for legislation to create a mandatory tunnel inspection program similar to the checks now required for bridges.

Senators John F. Kerry and Edward M. Kennedy of Massachusetts immediately introduced a bill that would require the US Department of Transportation to develop tunnel inspection guidelines for states and authorize the use of independent engineers to review construction methods on major federal highway projects.

US Representative Michael Capuano, who filed legislation last year to set up a national tunnel inspection system, praised the safety board for advocating mandatory inspections. "Before this tragic accident I had no idea the tunnels were not inspected on a regular basis," he said. "I presumed they were. I was wrong."

The ceiling at the eastern end of the I-90 connector was removed after the accident, and epoxy bolts elsewhere in the tunnel were reinforced with braces and another type of bolt.

State officials inspected all tunnels and determined that epoxy used to hold up the ceiling in the Ted Williams Tunnel is safe.

Attorney General Martha Coakley is conducting a criminal investigation of the accident and is expected to decide shortly whether to seek indictments. She would not comment on the safety board's findings or her own probe.

Governor Deval Patrick, who expressed anger over the findings, urged the attorney general "to hold accountable all those who should be held accountable."

"As I understand the report, it confirms the utter disappointment I have, and I think we all should have with Bechtel/Parsons Brinckerhoff," Patrick said. "Among the conclusions -- the wrong glue and the wrong leadership. The wrong oversight of the project has been confirmed by this report."

A lawyer for the Del Valle family said the board's findings suggest there was wrongdoing that warrants criminal prosecution.

"This report provides all manner of factual support for criminal indictments and no question about civil liability," said Brad Henry, one of the lawyers who has brought a multimillion-dollar lawsuit for the family against more than a dozen contractors and the Turnpike Authority.

But most contractors said the findings show their companies were not to blame, or they disputed the board's conclusions.

"We are still reviewing the findings of the NTSB report, but it seems to confirm our confidence in the integrity of our design and the accuracy of our calculations," Doug Bailey, spokesman for Gannett Fleming, said in a written statement.

He said the company "only approved the use of an epoxy that could have been the standard-set epoxy," not the quick-drying kind. "Only today did we learn that the wrong epoxy was used in the tunnel ceiling," he said.

In a strongly worded statement, Powers Fasteners insisted it supplied standard-set epoxy. "Powers did not know that Fast Set [quick-drying epoxy] was used for the ceiling in place of the Standard Set epoxy," it said. "It would be an absurd conclusion if the federal investigators were to consider Powers Fasteners in any way responsible."

Peter Mancusi, spokesman for Modern Continental, said in a written statement that the report makes clear that "Modern Continental fulfilled its obligations to install the suspended ceiling system in conformity with contract plans and specifications."

Andrew Paven, a spokesman for Bechtel/Parsons Brinckerhoff, said, "NTSB has performed a thorough and objective investigation of this tragic accident."

After a year of speculation over causes of the collapse, ranging from faulty installation by workers to cost-saving decisions to scale back the number of bolts used, the safety board determined one factor counted more than any other.

"Fundamentally, what we're talking about here is the wrong glue being used," said Kitty Higgins, one of the five board members.

The problem began with Gannett Fleming, ceiling designer. "They set a performance-based standard for the epoxy, that it had to be an epoxy of a certain strength," said Bruce Magladry, director of the board's Office of Highway Safety. "They did not specify an epoxy to use, but rather one that performs in a certain way."

Gannett Fleming failed to consider "creep," the fact that fast-set epoxy, due to its chemistry, breaks down and loses strength, while standard-set epoxy remains stable, the board's staff said.

"Should they have known?" asked Rosenker.

"They probably should have," said Magladry, adding "there was no malice" on the part of managers and engineers. "These were conscientious people trying to do their jobs. They didn't understand creep."

"Should they have known?" Rosenker asked again.

"It had been in the [engineering] literature," Magladry said. "I just don't think enough people understood it."

The contract specifications written by Gannett Fleming and reviewed by Bechtel/Parsons Brinckerhoff omitted any consideration of creep. "The shortcoming is that the specifications did not address the issue of the long-term characteristics of the epoxy," said Mark Bagnard, an NTSB investigator.

Modern Continental followed those specifications and contracted with a distributor, which in turned contracted with a supplier. Modern Continental, however, was not aware the epoxy it used was susceptible to creep and unsuitable.

Powers Fasteners, meanwhile, had tested its products for creep and found in 1995 that fast-set failed under long-term stress, such as the pull of gravity in overhead applications, the NTSB found.

Yet Powers did not highlight the fact of the fast-set breakdown in its dealings with Big Dig contractors, the staff said. "It was difficult to find -- it was in the fine print," said Magladry. "But even if they did find it, I'm not sure they would have understood it."

Later, when managers discovered within weeks of installing the bolts that they were slipping out, it was Powers that was in the best position to have averted the collapse, said Carl Schultheisz, a NTSB material lab analyst.

Once bolts slipped, didn't Powers, the one entity involved that was aware of the phenomeon of creep, question whether the right epoxy was used, asked NTSB member Debbie Hersman.

"We don't know why it wasn't asked," Schultheisz said. "Powers had the best opportunity to prevent this accident by raising that question."

Instead, Modern Continental, Bechtel/Parsons Brinckerhoff and other managers were convinced the cause of the slipped bolts was faulty installation, and indeed, the bolts examined after the accident had lost up to 40 percent of their strength because of voids, or air bubbles. But that alone would not have caused the collapse.

Dan Walsh, an NTSB engineer, said Bechtel/Parsons Brinckerhoff in 2003 produced an inspection manual for the tunnels, but it was not implemented by the Turnpike Authority during the 43 months between its completion and the ceiling collapse. "The bureaucratic delays are enough to set your hair on fire," Hersman said.