Authorities say that after a visit to Harvard University, dozens in a group of high school students and their adult chaperones were injured when their charter bus hit a bridge.
Police say the driver failed to heed low-clearance warning signs prior to the crash.
According to emergency officials, 34 people were injured, including one person with life-threatening injuries.
The Calvary Coach bus was heading to the Philadelphia area when it struck an overpass on Soldier's Field Road in Boston on Saturday evening. Some passengers were trapped for more than an hour as rescue crews worked to free them.
Authorities say the bus did not belong on that road and state police are investigating whether charges are warranted against the driver after apparently failing to see the sign prohibiting the vehicle from taking that route. Bus owner Raymond Talmedge said his driver was being interviewed by police.
The students were part of a Destined for a Dream Foundation group. Officials with the Bristol, Pa.-based group, a nonprofit that helps underprivileged youth, refused to comment on the crash when reached by phone.