Witnesses say a pregnant woman who was killed in a hit and run with her husband while they were headed to the hospital was thrown from the car and her body landed under a parked tractor-trailer.

Authorities say Nachman Glauber and Raizy Glauber, both 21, were pronounced dead at hospitals after a BMW slammed into the car they were riding in early Sunday in Brooklyn's Williamsburg neighbourhood.

Police said their baby boy was delivered prematurely at a hospital and was in serious condition.

Isaac Abraham, a community leader in the Orthodox Jewish neighbourhood, had said earlier Sunday that the couple was going to the hospital for the child's birth, but he later said it wasn't clear why the Glaubers were headed there.

Photo credit: Associated Press