A man was pronounced dead Sunday after he was found severely injured on a rocky embankment under a bridge in Hanover.Officials said Dartmouth College alumnus David Gallagher, 24, was in town with his family for the Class of 2020 commencement.Emergency services were called at 1:48 a.m. Sunday to get help for Gallagher, who was reported to be severely injured on the rocky embankment under the Ledyard Bridge on West Wheelock Street, police and fire officials announced in a joint news release."It's a very rocky, steep terrain," said Hanover police Capt. James Martin. "It's often inaccessible to walk in on foot from the roadway from Hanover."Since the terrain was rough, Gallagher was taken from the scene via a Dartmouth Department of Safety and Security pontoon boat to an awaiting ambulance."There have been situations in the past where people will go congregate in that area during the warmer months in the summer, so that is under investigation," Martin said. "At this time, we don't exactly know."Gallagher died at Dartmouth Hitchcock Medical Center, officials said.He wore the number 15 Dartmouth jersey on the lacrosse field and was a successful player all four years at school.Now, the Dartmouth community is mourning the loss of a life gone too soon."It's a very unfortunate event for somebody like this to be visiting Hanover celebrating a big achievement," Martin said. "Our prayers go out to the family and wish the best for them."Officials said no foul play is suspected at this time.The cause of death is being investigated by Hanover police, officials said.