NYPD searching for person of interest in fatal Bronx subway attack

NEW YORK -- The NYPD is looking for a person of interest in a fatal subway attack in the Bronx, reports CBS New York.

Wai Kuen Kwok, 61, was pushed onto the tracks and killed on Sunday morning. Kwok was with his 59-year-old wife, who was not injured but taken to the hospital because she was emotionally destraught, according to earlier reports.

Witnesses say that they saw a man push the victim before running out of the station and catching a bus, authorities told CBS New York. Investigators told reporters the man boarded a Bx35 bus and got off minutes later, entered a bodega and eventually left -- smoking a cigarette.

Surveillance video reportedly shows moments after the attack when emergency responders rushed to the scene and a visibly shaken woman -- believed to be the victim's wife -- was escorted into an ambulance.

The NYPD passed out fliers throughout the neighborhood, hoping for tips as they search for the person of interest. Police are offering a $2,000 reward for any information leading to an arrest.

Relatives of the victim, who asked the station not to be identified, expressed their heartbreak, saying that he was a good man. The family is desperate for answers, according to CBS New York.

"If they can find [the attacker], that would be great," a relative said.

It is not clear what led to the fatal shove, police say. The two did not exchange words, there was no struggle and it does not appear to be an attempted robbery.