Train passengers said the man was acting in "hostile and erratic manner".
A 30-year-old man, who was screaming on a subway in New York, died on Monday after another passenger grabbed him and placed him in a chokehold. A video of the incident was recorded by Juan Alberto Vazques, a freelance journalist, on his phone and posted on his Facebook page. The New York Times (NYT) said that the man's identity has not been released and quoted witnesses to report that he had been acting in "hostile and erratic manner" towards other passengers.
The video shows the man flailed his arms and kicked his legs as he attempted to free himself. Two other men are seen standing over them and helping subdue the man.
The man who moved to restrain him was 24 years old, NYT said in its report quoting police officials. The cops took him in custody, questioned him and released him.
The man has not been charged and an investigation is continuing, the outlet further said.
This chokehold is called a rear naked chokehold in martial arts and is applied from an oppnonet's back. It is an easy way to submit your opponent or render them unconscious if necessary since it cuts off the oxygen supply to the brain.
Mr Vazquez told NBC News that he was on an F train going northbound when the incident took place.
"The man got on the subway car and began to say a somewhat aggressive speech, saying he was hungry, he was thirsty, that he didn't care about anything, he didn't care about going to jail, he didn't care that he gets a big life sentence. That 'It doesn't even matter if I died'," Mr Vazquez said.
He added that other passengers got scared by his yelling. It was then that a co-passenger came up from behind and put him in chokehold.
The New York Police Department (NYPD) said it was called to the Broadway-Lafayette station around 2:25 pm after a 911 call of a physical fight on the train. The man was unconscious on the car floor when officers arrived, said NBC News.
Mr Vazquez said the chokehold lasted about 15 minutes, even as the train stopped at the Broadway-Lafayette station and the doors opened. All the passengers inside the train car left, except the three who had been working to subdue the man.
The police said that the man in the chokehold died at the scene. Mr Vazquez said no one thought the man would die.