Police probe fatal crashes

State police are investigating a pair of fatal overnight accidents in Stoughton and Westford.

Police say a 23-year-old Franklin woman was struck by at least one vehicle while walking in the high-speed lane of Interstate 495 north in Westford just before 4 a.m. Friday.

She was pronounced dead at the scene. What she was doing in the highway remains under investigation. No charges have been filed and the woman's name has not been released.

The accident forced the closure of all three lanes of traffic for about three hours.

Police say an SUV rolled over on Route 24 south in Stoughton just after 2 a.m. The driver, 51-year-old Neuza Nascimento of Fall River, was pronounced dead at the scene.

Police say she may have fallen asleep at the wheel. Her passenger, 54-year-old Jose Filho of Fall River, was seriously injured.