A man was shoved in front of an oncoming New York subway D train and died at the 167th Street subway station in the Bronx Sunday, the first time since 2012 that a rider was fatally struck after being intentionally pushed by someone onto the tracks.  The victim, Wai Kuen Kwok, 61, was standing on the subway platform with his wife around 8:45 a.m. when a stranger threw him into the oncoming train, the New York Times reported.

“I heard screams but at the time I didn’t know what was happening,” Yan Liang, one of the couple’s neighbors who was at the station shortly after Kwok was hit, told the Times. “Later, when I got home, I found out.”

The conductor later said he tried to stop the train, but did not have enough time. Several train cars rolled over Kwok before coming to a stop, according to the New York Post.

The suspect, wearing a black jacket, fled the scene but was caught on surveillance video leaving the subway station minutes after the attack. He then boarded a bus before going into a convenience store, where he emerged smoking a cigarette. Police said there was no indication the victim knew the killer and the attack appeared “to be random." 

Kwok’s wife, who witnessed her husband’s death, was taken to a hospital for trauma, according to CNN. She did not have any injuries. The couple was on their way to Chinatown for breakfast when the incident occurred.

The suspect has not been apprehended; however, authorities said they believe he lives in the vicinity of the station where the attack took place. Investigators have questioned the bus driver as well as the store employees about the assailant. “I want to know what’s happening in his head,” Kwok’s son told the Post.