NEW YORK (CBSNewYork) -- Police are investigating a deadly incident at a Harlem subway station.
It happened around 4 p.m. Saturday at the 110th Street Central Park North subway station.
Cell phone video shows a naked man who appears to be emotionally disturbed inside the subway station.
Police say that man approaches a stranger and, unprovoked, begins to attack him before pushing him onto the tracks.
Jose Ramos Diaz calls the incident a tragedy. He watched the push in horror and did the first thing he could think of to help -- he put his hand up to stop the incoming train.
Describing the moment, Ramos Diaz told CBS2's Kiran Dhillon, "It was something I cannot explain. It was something three-dimensional, like I wasn't in the real world."
He adds the situation quickly escalated after a Good Samaritan jumped onto the tracks to help the victim.
He says the emotionally disturbed person followed the helpful stranger and also started a dispute with him.
A man who did not want to be identified arrived on the platform to find all three men on the tracks.
"I was on the phone with 911 when I saw him get electrocuted," he said.
He watched as the naked man hit the third rail and died.
The Good Samaritan and the man who had been shoved onto the tracks were barely able to comprehend what had just happened to them.
"The guy that was trying to help the other guy, he was shaky. I offered him hand sanitizer ... I offered him some water and he said no. He was just shaky," he said.
Police say the original male victim and the Good Samaritan both suffered minor injuries.
They were taken to an area hospital for treatment.
As for those who witnessed the ordeal, they say it's something they won't soon forget.
"Just a little shaken because I have a daughter and I always tell her to be aware of her surroundings," the witness said.
They say they've seen many emotionally disturbed people in the subway system and wish they were getting the help they need.
The man who died has not been identified.
CBS2's Kiran Dhillon contributed to this report.
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