An investigation is underway after a 51-year-old man collapsed in the lobby of a downtown Vancouver hotel Friday and was pronounced dead at the scene.

Police haven’t deemed it a murder, but said the man was in an altercation with another man in front of the Lotus Hotel, a single room occupancy building, at 455 Abbott Street shortly before 8 a.m.

After the confrontation, the man entered the lobby of the hotel and collapsed. Paramedics were unable to revive him.

A 40-year-old man has been detained in connection with the incident, but no charges have been laid.

The man’s cause of death has not been confirmed.

Witnesses in the area said the victim lived in the building. One witness, identified only as Johnny, said the victim was still conscious when he was lying in the hotel lobby, and that he had been attacked but didn’t appear to sustain any obvious injuries.

“When I ran upstairs and grabbed my cell phone, I ran right down the stairs and phoned 911,” he said. “When I tried to give him mouth-to-mouth, he was already starting to turn blue at that point.”

The incident shut down a portion of Abbott Street near Pender for hours Friday as police investigated the scene.