BOSTON -- Big Dig safety being called into question again after a series of crashes which have lead to demands for a closer look at tunnel designs.

State Senate President Therese Murray has called for a review by the state Department of Transportation because of rectangular handrails that line about 6 miles of Big Dig tunnels, the Boston Globe reported.

The calls follow the deaths of seven people who were killed in crashes in the Big Dig tunnel system between 2004 and 2008, the Globe reported, all of them dying after hitting the handrails, with most of the victims dismembered. One person who survived lost an arm, the paper said.

A lawsuit has been filed in Suffolk Superior Court by the widow of a state trooper, Vincent Cila, who died in 2005 after he hit a handrail post in a motorcycle crash. He died after his neck was broken and he lost an arm.

The suit claims the design of the handrails is flawed and claims the posts that support the handrails have sharp edges that act like blades in a shredder.

Among the defendants in the suit are Bechtel/Parsons Brinckerhoff and the turnpike. Both said the handrails meet all applicable state, federal, and industry guidelines.

Friends and relatives of those killed said the handrails should be redesigned.