BOSTON (CBS) – A bus starting a trip from Harvard to Pennsylvania struck an overpass on Soldiers Field Rd., leaving 27 passengers wounded and three still trapped on the bus.

A private Calvary Coach bus was driving East when it struck the Western Ave. Bridge.

There were 42 passengers on board, and the MBTA is transporting uninjured passengers away from the crash site.

Soldiers Field Rd. is closed and traffic is being diverted.