The shot man was taken to Robert Wood Johnson University Hospital in New Brunswick where he died of gunshot wounds, Union County Prosecutor's Office spokesman Mark Spivey was quoted by the New Jersey news outlet as saying.
According to Spivey, a girl was wounded in the leg and was also taken to hospital, and a woman, who had also been shot, was treated at the scene.
The assailant managed to escape. Police cordoned off the area. Investigators are looking for shell casings and question residents.
The motives of the shooter are still unknown.