Gov. Mitt Romney said Tuesday he was taking legal action to oust the head of the Massachusetts Turnpike Authority after a woman was crushed to death by falling cement in a Boston Big Dig tunnel.

"People should not have to drive through the Turnpike tunnels with their fingers crossed," Romney said. "Neither I nor anyone else could be or should be satisfied until we have new leadership at the Turnpike authority."

At least 12 tons of concrete fell from the ceiling of a connector tunnel late Monday, crushing a car carrying newlywed to Logan Airport and killing the woman. The incident again raising concerns Tuesday about the integrity of the massive highway project in the central artery through the city.

Authorities said they were inspecting at least 17 other sections of the tunnel system where similar "tiebacks" were used to hold ceiling panels in place.

"I don't think anyone can feel the tunnels are safe, given what happened this morning," Romney told a New England Cable News reporter after touring the tunnel under an industrial area of South Boston where the woman died.

The driver of the crushed car managed to crawl through a window to safety, but his passenger was killed when four of the massive concrete ceiling panels hit the vehicle late Wednesday.

The debris and danger shut down the connector tunnel and backed up traffic for miles during the morning commute. Authorities hoped to reopen it midday Wednesday after removing about 30 ceiling slabs from the accident site and inspecting the area.

Massachusetts Turnpike Authority Chairman Matthew Amorello said a steel "tieback" that had held a 40-foot section of ceiling in place over eastbound Interstate 90 gave way, letting the concrete slabs loose as the car drove beneath them.

"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."

The accident was near the entrance to the Ted Williams Tunnel, which runs under Boston Harbor to Logan International Airport. Amorello said he had ordered a precautionary inspection of that tunnel as well because it similar tiebacks, though a different ceiling structure.

Amorello said similar tiebacks were also used in 17 spots on the Interstate 90 section of the Big Dig project, and all of those also were being checked.

"We feel awful about what happened last night," Amorello said. "It's an awful, awful tragedy. ... This is an awful situation that occurred."

He appointed a state police major, two outside consultants and a team from the Federal Highway Administration to assist in the investigation.

Boston Mayor Tom Menino demanded quick answers.

"We don't need a six-month study. We need an immediate reaction and action by the different authorities so that we can reassure the public as they drive into the city or drive over to the airport that the tunnel is safe to go through," he said.

The ceiling panels in the affected tunnel were erected in 1999. The steel tiebacks holding them were bolted to the tunnel roof overhead.

Amorello said the contractor was Modern Continental. Representatives of that company and project manager Bechtel/Parsons Brinckerhoff did not immediately respond to calls seeking comment Tuesday.

"Any responsible party will be held accountable for what happened," Amorello said. "This is an unacceptable, horrible tragedy."

The $14 billion Big Dig highway project, which buried Interstate 93 beneath downtown and extended the Massachusetts Turnpike to Logan Airport, has been criticized for construction problems and cost overruns. 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.

Christy Mihos, an independent candidate for governor and former member of the Turnpike Authority Board and agency critic, called the accident "my worst nightmare come true."

Mihos urged the governor to seize control of the Turnpike's day-to-day operations.

The victims were identified by State Police Tuesday as Milena Delvalle, 38, and Angel Delvalle, 46.

Delvalle was treated for minor injuries. "There was only about 6 to 12 inches. But he was able to get through," State Police Maj. Michael Mucci