Firefighters inspect a section of ceiling in the Interstate 90 connector tunnel eastbound through Boston that collapsed onto the roadway

Massachusetts Governor Mitt Romney says his office has begun taking legal steps to remove the head of the state's Turnpike Authority following a deadly accident in a Boston tunnel.

Romney said Tuesday it is time for change and he has instructed his legal counsel to find a way to remove Matt Amorello from his post.

Also on Tuesday, the state attorney general Tom Reilly launched a criminal probe into the incident.

The developments come one day after a three-ton concrete panel fell from a ceiling that is part of the so-called "Big Dig" tunnel system late Monday, killing a woman in a car.

Inspectors are working to ensure that 100 similar ceiling panels pose no danger. The Big Dig has become a central route through Boston.

The biggest public works project in U.S. history, the 15-year-long, $14-billion undertaking has been plagued by cost over-runs and water leaks.