Two people were killed in a fiery crash on a New Jersey highway Monday evening when a tractor-trailer overturned, trapping a car underneath as both vehicles burst into flames, authorities say. Essex County prosecutors say that the tractor-trailer flipped onto the car on New Jersey Route 21 in Belleville at about 7:30 p.m. The two vehicles burst into flames, and a third car also crashed but didn’t catch fire. Two of the passengers in the car that was on fire were pronounced dead at the scene, authorities say. The drivers of the other two vehicles were uninjured.