Boston's Big Dig crisis deepened Thursday when Gov. Mitt Romney shut down the eastbound lanes of a major highway tunnel after two problem bolts were discovered in the ceiling.
The Ted Williams Tunnel, which carries traffic to and from Logan Airport under Boston Harbor, already had been limited to bus traffic since ceiling panels in a connector tunnel collapsed this month, killing a car passenger.
State engineers discovered that two bolts appeared to have slipped a half-inch and 1 inch in one ceiling panel, Romney said. He added that he expected the Ted Williams Tunnel to be shut down for hours, not days.
"It is perhaps an overreaction, but we want to err on the side of public safety," Romney said at a news conference. He said he was overruling an earlier finding by the Massachusetts Turnpike Authority that the tunnel was safe.
It was in a tunnel leading to the Ted Williams that 12 tons of concrete ceiling panels fell on a car July 10, killing 39-year-old Milena Del Valle.
That connector tunnel, a stretch of Interstate 90, was shut down immediately, and inspections found hundreds of problems with bolts holding its ceiling panels in place.
After the collapse, engineers conducted "pull tests" on the ceiling panels in the connector tunnel and a tunnel ramp and found hundreds of bolts, secured with epoxy, that were unreliable. Similar tests have not been done yet in the Ted Williams Tunnel.
The panels in the Ted Williams Tunnel are suspended using the same threaded epoxy bolts, but the panels are lighter than in the connector tunnel and the system that suspends them is considered more substantial, using wider bolts.
Romney said the new information by his own inspection team prompted him to immediately close the 11-year-old tunnel to all traffic. A special truck was brought in to shore up the ceiling. Engineers were working to come up with a permanent plan to reinforce the panel and allow traffic to pass, he said.
Romney deflected criticism that he hadn't moved fast enough to notify city officials and federal transportation agencies before shutting down the tunnel.
"The first action was to shut the tunnel, and then we began making the calls," Romney said.
The Republican governor, who is considering a run for president, has started proceedings to oust Matthew Amorello, the head of the Turnpike Authority, saying he has failed in his oversight and leadership of the Big Dig.
A spokesman for Amorello had no immediate comment on Romney's decision to overrule the authority's determination that the tunnel was safe.
The $14.6 billion Big Dig buried the old elevated Central Artery under Boston. Although it's been considered an engineering marvel, the most expensive highway project in U.S. history also has also been plagued by leaks, falling debris, cost overruns, delays and problems linked to faulty construction.
Attorney General Tom Reilly has launched a criminal investigation into the collapse and is considering whether involuntary manslaughter charges are warranted. His inspectors are focusing on how the concrete panels were designed, whether they were secured properly for their weight and whether they were tested properly.
The mounting costs of problems with the tunnels range from hundreds of thousands of dollars in lost tolls to a loss in tourism. On Thursday, about 50 business leaders met with Lt. Gov. Kerry Healey, who has been appointed by Romney to address the concerns of the Boston business community.
"There's a general mindset, I believe, throughout the state right now that if you can avoid coming into Boston, perhaps that's the right thing to do," Healey said. "I think the message we need to send out today is that you don't need to do that, that in fact you should come to Boston, that Boston is open for business."