"Empty" tanks are sometimes more explosive than full ones! This sounds like a real pipe bomb, and if it was strapped to three tanks that only contained vapor, then it could have done some SERIOUS damage.
Sounds low-tech though, so probably not any organized element, just some hoodlums or pranksters that went way too far!
edit on 2-11-2012 by
darkhorserider because: (no reason given)
