the 650-ton Atlas pulsed-power generator discharged nearly 19 million amps of current
O.K., who likes their toast really
I'd go with the capacitive store idea as well. Even a very small capacitance can demonstrate this. An old trick was to charge an electrolytic capacitor up on the B+ line of some piece of equipment, then discharge it across the lid of a can or some similar object. The crack is produces is quite loud even for the relatively small charge involved (e.g 250V on a 32uF capacitor = 8000 coulombs).