Last night, MassDOT didn’t rule out turning the Michael J. Tobin Memorial Bridge into an underwater tunnel. It’s been a mainstay in the Boston area since cars started driving on it back in 1950.

State officials are considering replacing the 74-year-old Tobin Bridge with a tunnel, prompting mixed reactions from Boston and Chelsea residents. Iris Arroyo said she won't drive over the bridge.

That group also includes Boston’s Tobin Bridge and the Sagamore and Bourne bridges on Cape Cod. The NTSB said its report “does not suggest that the 68 bridges are certain to collapse,” however.