More 30 high schools students and their adult chaperones were injured, after their bus hit an overpass in the US city of Boston.
Authorities said the group were returning to Philadelphia, Pennsylvania on Saturday evening after a visit to Harvard University when the driver hit a bridge after failing to heed low-clearance warning signs.
Emergency officials reported that 34 of the 42 people travelling on the Calvary Coach bus were injured, adding that one of the victims is in a life-threatening condition.
It is reported that the bus driver had seen the bridge on his GPS monitor when it was too late for him to avoid the crash.
The bus suffered significant damage after the accident and some passengers were trapped in it for an hour, while firefighters were trying to lift the roof off.
The driver, however, did not suffer any injuries. An investigation into the crash will determine the charges that will be filed against him.
The students were from the Destined for a Dream Foundation group, which is a nonprofit organization that helps underprivileged teenagers.