HANOVER — Acting swiftly, Dartmouth College has suspended two Greek organizations involved in a social event where heavy drinking was reported, after a student who attended the party is believed to have died by drowning in the Connecticut River on Saturday.

Dartmouth said late Tuesday afternoon that it suspended fraternity Beta Alpha Omega and sorority Alpha Phi, as the college is cooperating with Hanover police in their investigation into the circumstances of the death of Won Jang, a 20-year-old member of the class of 2026 whose body was recovered from the river on Sunday after he had not been seen since previous evening.

“Dartmouth has suspended two Greek organizations, Beta Alpha Omega and Alpha Phi, as the investigation continues, and we are working closely with the Hanover Police Department, which is leading the investigation,” Dartmouth spokeswoman Jana Barnello said via email.

Jang, from Middletown, Del., a member of Beta Alpha Omega, was residing at the fraternity during what is known as “sophomore summer,” when sophomores spend the term in session on campus before entering their junior year in the fall term.

Under the Dartmouth suspension policy, a Greek organization is prohibited from hosting events, recruiting new members or collecting dues from members, all bans that curb the organizations’ ability to participate in Greek life on campus.

Dartmouth did not provide a reason for the suspensions, but both Greek organizations had been subject to recent disciplinary actions imposed by the college, according to Barnello. At the time of Jang’s death, Beta Alpha Omega was on alcohol probation after having been suspended through the 2023-24 fall, winter and spring terms. The probationary period began when the summer term began June 20.

Alpha Phi was placed on alcohol probation during the fall 2023 term and was reinstated to good standing beginning with the winter term.

Hanover Police Chief Charlie Dennis said police received information that Jang’s presumed drowning might be related to a social event that involved drinking and “hazing” although police did not know as of Monday whether the purported event was an “official” event occurring at the Greek organizations or an unofficial social gathering that occurred off campus.

Jang was last seen around 9:30 p.m. on Saturday in the area of the docks near Ledyard Bridge and the Dartmouth boathouse and was reported missing the next day after he did not appear for a scheduled appointment on Sunday, according to NH Fish and Game, which supervised the recovery operation involving Upper Valley police and fire departments.

Neither Beta Alpha Omega nor Alpha Phi responded immediately to messages for comment on Tuesday evening.

Contact John Lippman at jlippman@vnews.com.