BOSTON (AP) – Cost-overruns. Delays. Criminal investigations. Flooding. Problems have long plagued Boston’s Big Dig highway project. Now comes a ceiling collapse ending in death.

The only solace state officials could take on Tuesday was that the accident killed just one person on a system of roads used by 200,000 vehicles a day.

The collapse of at least 12 tons of concrete onto a car in a tunnel prompted renewed scrutiny of the troubled $14.6 billion project, which buried the city’s central artery underneath downtown and is already the costliest highway construction program in U.S. history. The state attorney general planned to treat the tunnel as a crime scene that could lead to negligent homicide charges.

The collapse happened around 11 p.m. Monday, when the underground highways were relatively free of traffic. Four concrete slabs weighing three tons each pancaked onto the passing Buick sedan, killing Milena Del Valle, who was riding on the passenger side, which bore the brunt of the collapse. Her husband managed to crawl to safety through a window that was only a foot wide. He suffered only minor injuries.

By Tuesday, the attorney general’s office had begun issuing subpoenas to those involved in the design, manufacturing, testing and construction of the concrete panels and tunnel.

“What we are looking at is anyone who had anything to do with what happened last night,” Massachusetts Attorney General Tom Reilly said. “No one is going to be spared.”

Debris shut down part of Interstate 90, backing up traffic for miles Tuesday. Authorities hoped to reopen it Wednesday, but they were still removing about 30 ceiling slabs from the accident site and checking at least 17 other areas with similar “tiebacks” holding ceiling panels in place.

Gov. Mitt Romney pinned much of the blame on the head of the Massachusetts Turnpike Authority and promised to take legal action to oust Matthew Amorello. He compared the situation to the replacement of former Federal Emergency Management Agency chief Michael Brown after Hurricane Katrina.

“People should not have to drive through the Turnpike tunnels with their fingers crossed,” said Romney, a longtime critic of Amorello.

The trouble-plagued Big Dig has gained nationwide notoriety for rising costs, years of traffic snarls, a criminal investigation into faulty concrete from suppliers and problems with hundreds of leaks that sprouted in another of the Big Dig tunnels.

Amorello said the tunnels are safe and said he would not step down. “We will work on all of this, together, cooperatively,” he said.

“This is a horrible, horrible event,” Amorello said. “It was an anomaly, and we will get to the bottom of it.”

Christy Mihos, an independent candidate for governor and former member of the Turnpike Authority Board and agency critic, had urged Romney to seize control of the Turnpike’s day-to-day operations, calling the accident “my worst nightmare come true.”

The section that collapsed was near the entrance to the Ted Williams Tunnel, which runs under Boston Harbor to Logan International Airport. That segment of the tunnel was completed in 1995-96, but the ceiling panels were installed in 1999.

Modern Continental, the contractor of that portion of the project, issued a statement that its work “fully complied with the plans and specifications provided by the Central Artery Tunnel Project. In addition, the work was inspected and approved by the Central Artery Tunnel Project.”

Andrew Paven, a spokesman for project manager Bechtel/Parsons Brinckerhoff, said the company was working with the Turnpike Authority to help pinpoint the cause and to prevent future accidents.

Amorello said a steel “tieback” that had held a 40-foot section of ceiling over eastbound Interstate 90 gave way, letting the concrete slabs loose as the couple drove beneath them on their way to Logan Airport to pick up relatives returning from a vacation.

“There was a snapping sound heard,” Amorello said. “One of the tile panels from the roof released. It caused a series of panels to be released.”

Amorello appointed a state police major, two outside consultants and a team from the Federal Highway Administration to assist in an investigation into the cause of the collapse.

The highway project, known formally as the Central Artery and Third Harbor Tunnel project, buried Interstate 93 beneath downtown and extended the Massachusetts Turnpike to the airport.

The idea for the Big Dig was conceived in the 1970s, but construction did not begin until 1991. Over the years, it has faced repeated criticism for its ballooning cost and a variety of construction problems. There have been water leaks and at least one incident when dirt and debris from an air shaft fell onto cars.

In May, prosecutors charged six current and former employees of a concrete supplier with fraud for allegedly concealing that some concrete delivered to the Big Dig was not freshly mixed.

Amorello said preliminary investigation shows that the quality of the concrete was not to blame for Monday’s accident.

Commuter seemed unfazed by the accident – in part because there are few options to avoid getting in and out of the city without using the Big Dig.

“You can’t really change your route around that area,” said Liz Morrison, 24. “It’s just really fast, efficient and the best way to get through the city, especially to the airport. It’s really the only way.”

—

Associated Press Writers Glen Johnson, Brooke Donald, Steve LeBlanc, Jimmy Golen and Denise Lavoie contributed to this report.

—

On the Net:

Big Dig: http://www.massturnpike.com/bigdig/index.html

Copy the Story Link