Investigations may close Boston tunnel for weeks

More than 240 loose ceiling bolt fixtures are scattered throughout the I-90 connector tunnel, said Turnpike Authority officials, who announced Thursday that the tunnel could remain closed for weeks as engineers determine whether to repair or replace the tunnel's drop ceiling.

The suspect bolts were holding up bulky concrete ceiling panels over every lane of the heavily-traveled tunnel, where panels collapsed Monday night, killing Milena Del Valle. Law enforcement officials investigating the 38-year-old Jamaica Plain woman's death are focused on the failure of bolt-and-epoxy fixtures.

Despite the existing federal and state investigations, lawmakers on Beacon Hill and Capitol Hill — facing unprecedented public outcry over the Big Dig's most recent and tragic failure — called for additional probes.

Governor Mitt Romney demanded and received legislative approval Thursday for his administration to take over safety inspections of the connector tunnel and to decide when and if it can reopen to traffic. The bill approved by the House and Senate Thursday night also calls for a $20 million "stem to stern" safety review of the Central Artery system.

Also, the entire Massachusetts congressionalcongrecsional delegation asked federal safety officials Thursday to launch a separate inquiry into Del Valle's death and to inspect all the Big Dig tunnels. The National Transportation Safety Board quickly dispatched a six-member civil engineering group to Boston to inspect the accident scene and determine whether a full-scale investigation is warranted.

The Turnpike Authority has started its own inspections of all Big Dig tunnels.

Even before the investigations are complete, a Wall Street rating firm said the $14.6 billion Big Dig's latest troubletroublew could mean taxpayers will have to pay even more to cover the project's costs. Moody's Investors Service officials said they were considering downgrading the project's credit rating, which means the future cost of borrowing for the project could rise.

The problems with the connector tunnel went unnoticed until after Monday night, when the car Del Valle was riding in to Logan International Airport was crushed by two ceiling panel sections that had come loose.

Each panel was secured to the top of the I-90 connector tunnel by bolt fixtures that include the bolts, epoxy, and metal plates. Tieback rods hang from the plate and suspend steel beams supporting the concrete panels.