Boston's Troubled Tunnels

A sign warns of a detour around the closed connector tunnels for Interstate 90 as a tractor trailer heads into the Ted Williams tunnel westbound from Logan Int'l Airport in Boston, Monday, July 17, 2006. Days after tons of ceiling panels came loose and fell on a car, crushing a passenger, Mass. Gov. Mitt Romney announced that inspections had found at least 242 points where bolts were separating from the tunnel roof.

Massachusetts Gov. Mitt Romney, right, looks over bolts in the ceiling of a Big Dig tunnel while speaking with Alexander Bardow, center, Director of Bridges and Structures, and Secretary of Transportation John Cogliano, Tuesday, July 18, 2006, in Boston. On Thursday, July 20, Romney ordered an immediate shutdown of the eastbound lanes of the Ted Williams Tunnel, the underground freeway leading to Boston's Logan airport.

The old style ceiling bolt in a Big Dig tunnel is seen on the left and the replacement style on the right, as workers make repairs and upgrades to a tunnel in the project, Tuesday, July 18, 2006, in Boston. Two tunnels were closed for inspections and repairs after 12 tons of ceiling panels fell, killing 38-year-old Milena Del Valle as she and her husband drove through the tunnel July 10 on their way to the airport.

Emergency personnel work at the scene of a ceiling collapse in the Interstate 90 eastbound tunnel through Boston that crushed a car, rear, killing a woman passenger, Tuesday, July 11, 2006. At least 12 tons of concrete fell from the ceiling of the tunnel, raising concerns about the integrity of the massive highway project that is the central artery through the city.

Firefighters inspect a section of ceiling in the Interstate 90 connector tunnel eastbound through Boston that collapsed onto the roadway and killed a woman passenger in a car.

This 2005 photo provided by the Delvalle family shows Milena Delvalle, of Boston, who was killed when concrete ceiling panels fell onto her car in one of Boston's Big Dig tunnels late Monday night, July 10, 2006. (AP Photo/Delvalle family via The Boston Globe)

Workers examine debris and concrete slabs Tuesday, July 11, 2006, that fell from the ceiling of the eastbound lane of the Interstate Route 90 connector tunnel late Monday in Boston. Falling cement killed a female motorist driving through the tunnel.

An opening is visible in the ceiling of a Big Dig tunnel in Boston, Tuesday, July 11, 2006, where cement ceiling panels fell late Monday night. A woman died and her husband injured when their car was crushed by the falling panels.

Men work Tuesday, July 11, 2006, near where cement slabs fell from a Big Dig tunnel late Monday night in Boston. The falling slabs crushed a passing car, killing a woman and injuring her husband. Twelve tons of concrete fell from the tunnel ceiling, raising concerns about the integrity of the massive highway project in the central artery through the city.

Workers walk from a Big Dig tunnel in Boston Tuesday, July 11, 2006, where cement ceiling panels fell late Monday night from the open area visible in the center of the photo. A woman died and her husband was injured when their car was crushed by the falling panels.

Massachusetts State Troopers and a highway worker (wearing hard hat) inspect hardware removed Tuesday, July 11, 2006, from a Big Dig tunnel where cement slabs fell late Monday night in Boston. The falling slabs crushed a passing car killing a woman and injuring her husband.

Slabs of concrete ceiling panels are shown stacked outside a Big Dig tunnel,Tuesday, July 11, 2006, in Boston. At least 12 tons of concrete fell from the ceiling of the tunnel, crushing a woman in a car and raising concerns about the integrity of the massive highway project that is the central artery through the city.