The danger isn't in rupturing a tank, doofus.
The danger is an unknown leak from one or more tanks releasing enough gas to provide a cloud of ignitable mixture.
It's the same reason you're supposed to turn your car off when fueling. A spark exiting your tailpipe is unlikely, but not impossible, and gasoline vapors near the ground could be ignited.
If you think that sounds ridiculous, check this video.
Gasoline vapors were ignited from a static spark by tugging on a sweater.
I have a hearty chuckle every time I see one of these things. Like spinner wheels, they're functionless wastes of money to make a statement, and that statement is "I am incredibly, just absolutely unbelievably stupid."