Two residents of a Bronx building housing formerly homeless veterans got into a fight on the street outside that left one of them stabbed to death Saturday night.

The name of the 50-year-old victim was withheld pending family notification.

The stabber fled and cops were searching for him.

A resident who has lived in the building for five years saw what happened from his window.

He said the victim, who may have been drunk, “instigated it.”

The attacker, he said, “bent down and told the victim, ‘I got something for you’ before knifing him in his chest.

The witness said they were fighting over “something stupid.”

The building is city-owned but run by Volunteers of America.