When calculating stresses in tanks, a common engineering tool is a technique called Hoop Stress. Imagine the tank composed of hoops stacked on top of each other. The strength of the tank is the sum of all of those hoops minus the hoop at the compromised location. The total loss in strength is really insignificant.
But then again, I am just an idiot who doesn't know my butt from a hole in the ground. You should smash the tank just to make everyone happy.