Massachusetts State Police say 28 of the people who were injured when a bus struck an overpass in Boston have been released from the hospital, while seven remain hospitalized.

Of the seven still hospitalized, one is in critical condition, four are in stable condition, one is in serious condition and one is awaiting discharge.

The bus was carrying a group of high school students and their adult chaperones home to the Philadelphia area after a visit to Harvard University when it crashed into the bridge Saturday night.

Authorities say the bus did not belong on Soldiers Field road, where a 10-foot height limit is in place and oversized vehicles are not authorized.

Ray Talmedge, the owner of the Philadelphia-based Calvary Coach Bus company, told WCAU-TV that driver Samuel Jackson looked down at his GPS and saw the bridge too late.