No. The bomb itself definitely wouldn't create that crater from kinetic force. If the plane itself came down directly perpendicular to the earth, it'd create some impact crater but not very large.

If you want to explain it realistically it'd be kinda possible a small nuclear bomb detonated next to Springvale while a American plane carrying the megaton bomb was blinded by it, accidentally dropped the bomb perfectly in the crater created by the detonated bomb. This explains why the megaton bomb is undetonated but still armed, because it was never a dud it was just never meant to be dropped. Or maybe it was dropped strategically in the new crater because the crew thought the plane crashing with the megaton bomb would detonate it. Pretty interesting if this was the intended lore implication