On a cold December morning, a group of businesspeople await the arrival of their 7:12 a.m. commuter train that will take them to yet another day at work. As they clutch their steaming cups of coffee or perhaps text colleagues from their smartphones, a local freight train rumbles past on the far track much like it has on so many other mornings – this scenario is quite routine. On this particular morning the freight train is hauling a string of generally nondescript black tank cars with yellow numbers and lettering. None of the commuters pay any attention to the fact that some of them bear red diamond placards lettered “flammable” while others carried black-and-white diamond placards lettered “corrosive.” The fact that each tank car bears four letter reporting marks 1 ending in “X” was not only of no concern to the bystanders on the station platform, but not a one knows what that means.