The incident happened just after 1:30 p.m. at 2448 University Ave. in the University Heights section.
Officers found a 34-year-old man with a stab wound to the chest on the second floor of the building.
The victim was taken to St. Barnabas Hospital, where he was later pronounced dead.
A police officer had to help the victim's mother up the stairs at her home in the Bronx following the deadly stabbing.
Eyewitness News reporter Jim Dolan spoke to a woman named Evelyn, who says she's known the victim his whole life.
"I just feel bad for the mother, she's sick and now she has to go through this," she said. "He's in his early 30s and to get his life taken like that is horrible."
Witnesses told Eyewitness News that the victim was coming home when he was confronted by a man who punched him in the face. The incident seemed to be over, but the man came back with two friends and a machete and stabbed the victim repeatedly in the chest.
The victim's fiancé left the building Wednesday night in tears. Friends say the victim worked hard and had never been in trouble with the law.
"He's not a loner, but more of a homebody," said a friend of the victim. "He works all the time. He's always paying attention to his girlfriend, he's taking care of his mom all the time."
He said he was with the victim earlier in the day, and was there when police told his mother her son was dead.
"That was the biggest heartbreaker I've ever seen because I've never heard somebody scream that way," he said.
Police are looking for three men who ran from the scene.
No arrests have been made, and the investigation is ongoing.
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