To elaborate, the rocket can take only about 1 atmosphere of pressure in the radial direction, but much more force in the longitudinal direction. It's designed to withstand the stresses of going in a straight line, but as soon as it bends it'll crumple, like a toilet paper cardboard tube.
So when the thing topples over, it bends. And when it bends, it ruptures because it's far in excess of the loads under standard conditions.
So when the thing topples over, it bends. And when it bends, it ruptures because it's far in excess of the loads under standard conditions.