WEST WINDSOR — A school bus accident in Mercer County is believed to have been caused when the 73-year-old driver suffered what ended up being a fatal medical issue.

The bus crashed on Wednesday afternoon while carrying seven students from West Windsor-Plainsboro High School South on Zaitz Farm Road. Police say the bus went off the road, hit a tree branch and then hit another tree before coming to a stop. The bus sustained only minor damage.

Police said after the crash students tried to help the driver before first responders arrived.

One of the students reported pain in her wrist.

The West Windsor Emergency Services and Capital Health MICU treated the driver before he was taken to University Medical Center at Princeton Plainsboro where he was pronounced dead.

The Mercer County Prosecutor's Office Serious Collision Unit also responded to the scene, as did West Windsor-Plainsboro Superintendent David Adderhold.

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