Graduate student Patrick David Casey died following a verbal altercation that turned physical Friday. He was 33 years old.

Casey, who was earning a master’s degree at the Elliott School of International Affairs, saw three individuals arguing outside the McDonald’s restaurant at 1916 M Street at about 2:40 a.m. that day, according to police documents. The fight “escalated into a physical confrontation” and D.C. Fire and EMS officials later transported Casey to GW Hospital for a gash to his nose and the back of his head.

Witnesses saw a 6-foot suspect, whose gender is not listed in police records, punch Casey, leading him to fall backwards onto the pavement. They also reported that the three suspects fled the scene in an unknown direction.

The time of Casey’s death following the incident is still unknown.

A conclusion on both the cause and manner of his death are still pending, Beverly Fields, chief of staff at the D.C. Office of the Chief Medical Examiner, said.

Casey served in the U.S Army Infantry and returned last year from Afghanistan.

“I have visited his family, as have other members of the university leadership, to offer our support. Our thoughts and prayers are with his family and friends during this time of extraordinary loss,” University President Steven Knapp said. “Patrick’s family has begun to make funeral arrangements, and we will work with them and his friends to memorialize his life.”