A fired construction worker returned to his Hell’s Kitchen job site and shot a supervisor, law-enforcement sources said yesterday.

Louis Lamburini, 56, a master mechanic, was sitting in a company van on Ninth Avenue near West 49th Street at 9:30 p.m. Sunday when the attacker walked up and shot him in the shoulder, cops said.

Lamburini, employed by Judlau Water Works in Queens, was rushed to Bellevue Hospital, where he was in stable condition.

Witnesses said they saw the gunman fire several shots then flee in a white vehicle along 49th Street.

Edward Conway, Judlau’s director of health and safety, said of the victim, “I’ve known the guy for years. He’s actually a friend of mine . . . so it’s hard.”