Boston Gov. Mitt Romney on Monday dramatically raised the number of potential trouble spots identified by engineers and investigators in a Big Dig connector tunnel where the ceiling collapsed.
Romney, speaking at a Statehouse news conference and illustrating his points with charts and diagrams, said that tests show more than 1,100 bolt assemblies that used epoxy and more than 300 other areas in the connector tunnel complex are unreliable. All, he said, will have to be reinforced.
Last week, days after 12 tons of ceiling panels came loose and fell on a car, crushing a passenger, the governor announced that inspections had found at least 242 points where bolts were separating from the tunnel roof.
Two Big Dig tunnels have since been closed, and Romney has not yet cleared the way for them to reopen.
The suspect bolt assemblies the governor described Monday used epoxy, and are the same type as the ones that failed, causing the fatality. Thousands of other bolt assemblies in the tunnel complex were constructed differently and are not believed to pose a risk.
Atty. Gen. Tom Reilly, who is considering filing involuntary manslaughter charges in the ceiling collapse, said Monday that investigators had discovered documents showing there was a "substantial dispute" from 1999 to 2000 over whether the design of the tunnel was adequate to hold the weight of the 3-ton ceiling panels.
Reilly, who refused to give specifics, said he did not know how the dispute was resolved.
Commuters on Monday endured increased traffic hassles with the closing of a second tunnel ramp connecting two interstates. It was closed Sunday after testing showed dozens of problems with the bolts holding up the ceiling. That ramp had been used as part of a detour around the accident scene.
Romney said engineers successfully tested a system to reinforce the bolts. With crews working around the clock, at least one portion of the closed areas could reopen by late in the weekend, he said.