A young boy was killed and three others were seriously injured in a two-vehicle crash Saturday on the Atlantic City Expressway, state police said.

A sports utility vehicle, driven by Jillian Nimmo, 26, of Sickerville, was heading west when it may have been changing lanes and clipped a car, according to police.

A six-year-old boy in the SUV died at the scene when both vehicles went off the highway and into trees off the shoulder. Nimmo was flown to a nearby hospital.

The driver of the car, Jerome Fogel, 89, of Westmont, and his passenger, Loretta Gregorio, 82, of Haddonfield, were also flown to a nearby hospital.

The two vehicles collided shortly before 2 p.m. at mile marker 16.2 near Egg Harbor in Hamilton Township. The six-year-old boy was a passenger in a car driven by a woman. The boy's relationship to the woman was unclear. The elderly man was driving with an elderly woman passenger, Sgt. Gregory Williams said.

The boy was pronounced dead at the scene. Traffic was delayed for about 10 minutes as a helicopter landed on the expressway to fly the elderly man to an Atlantic City hospital, Williams said. The conditions of the two women were not immediately known.

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