You knock both towers down, but offscreen out of respect for our fallen heroes. The cans fall back into the exact heap they started in, due to the can equivalent of "muscle memory", which you have discovered is a thing after many years of bunker life and fucking around with cans.
That was a nice thought though, by the mirthful angel known as "homestuck.com", which isn't a person, it's a fucking website, but you guess anybody can be called anything these days. Actually you changed your mind, you're switching homestuck.com from mirthful to mirthless.