State police say it appears a car crossed from the northbound side of the interstate to the southbound side, resulting in a crash at 10:30 a.m.
A 27-year-old Middleborough man, who had been trapped as a result of the crash, and who had serious injuries, was sent by LifeFlight helicopter to UMass Memorial Medical Center in Worcester, said police. A second person, a 25-year-old woman, was taken by ambulance to Rhode Island Hospital.
The Franklin, Wrentham and Bellingham fire departments sent crews to the crash site, near Exit 17.
About an hour later, a second crash occurred in the northbound lanes of I-495. State police said no one was injured in that crash, which was blamed on people watching activity at the site of the first crash as they drove by.
The crashes closed portions of both the northbound and southbound sides of the highway at times.