Man pushed in front of NYC subway train, killed NEW YORK Police on Monday night released new surveillance video in the search for a suspect who shoved a man onto the subway tracks, where a train struck and killed him. The incident occurred around 12:30 p.m. Monday at a subway station at 49th Street and 7th Avenue, just blocks from Times Square, reports CBS Station WCBS. Ki Suk Han, 58, of Elmhurst, was hit by a southbound train after he was pushed onto the tracks. The video shows the men arguing seconds before police say the suspect shoved Han to his death. The men are not believed to have known each other. Han was taken to Roosevelt Hospital, but he is believed to have died at the scene, crushed in the narrow space between the train and the platform. It was a sight so terrible that the conductor had to be treated for trauma. A surveillance image of the man wanted for allegedly pushing a man in front of a subway train in Midtown, killing him. Witnesses said Han was still alive in the moments after he was struck. "He was moving, he was shaking his head up and down," witness Joel Parkington told WCBS correspondent Lou Young. I left before he stopped breathing. When I was leaving, was still alive. At Han's home Monday night, police delivered the awful news, and escorted a woman from the home on 57th Avenue in Elmhurst. As of Monday night, the killer remained at large. Police are searching for a person of interest who is described as a black male in his 20s or 30s, around 5 feet 10 inches, weighing approximately 240 pounds. He was wearing a grey T-shirt, a down coat and a beanie-style knit cap. The man is also described as having short dreadlocks.