Two members of a Dartmouth College fraternity and a sorority have been charged in relation to the death of a student, who was found dead in a river over the summer after attending an off-campus party where alcohol was allegedly served to people who were under 21.

Won Jang, 20, was a student at the college and a member of the Beta Alpha Omega fraternity. Jang had attended an off-campus party in July hosted by the sorority Alpha Phi, according to a statement released by the Hanover Police Department in New Hampshire. The department said Jang and most of the other attendees were under 21 years old and drinking alcohol that was bought and served by Beta Alpha Omega members who were over 21.

After the party, several attendees decided to go for a swim in the Connecticut River, but when a heavy rainstorm occurred, many of them left in groups.

“No one in these groups noticed that Jang was unaccounted for. It was confirmed via multiple interviews, to include Jang’s family, that he could not swim,” Hanover police said in a statement.

A later autopsy report confirmed that Jang’s cause of death was drowning, and he had a blood alcohol limit of .167, which is more than twice the state’s legal amount allowed for drivers 21 and older.

Two members of Beta Alpha Omega fraternity, Matthew Catrambone and Samuel Terry, both 21, were each charged with a misdemeanor for providing alcohol to persons under 21 years old. The Alpha Phi sorority as a whole was also charged with a misdemeanor violation of facilitating an underage alcohol house, the police also said.

Police are continuing to investigate whether hazing was involved, which could lead to potentially more charges being levied towards people involved in the incident.