The damage looked more extensive than you’d expect from just a car crashing into the place. But it looked less extensive than you’d expect from a bomb. Maybe it was a poorly constructed bomb?
The force of an explosion in open space often goes skyward. Less damage to the surface, more to any objects lateral to the center of the blast. That is why trucks, which terrorists may load with explosives and gasoline trailers are not allowed on the lower level of the George Washington Bridge.
They probably ordered the parts from teamu or wish. Nothing is ever as big as it looks in the photos from those places.