It seems the fire-fighers at Ellsworth AFB wanted to make shure everything was hunky-dory with the automated fire extinguishers in the B1 Hangar. What to do? What to do? Well, you hang it up from a scaffolding, and turn it on. After a few seconds operation, you can check pressures etc, then turn it off. After 15 seconds you can see foam is covering all areas it has to, so the test is successful. Shut 'er off.... ...except the 'Off' switch appears to be 'Inop'... Errrr....chaps? Switch it off? Oh dear. The 'Off' switch is indeed 'Inop' and the foam continues to flow for several minutes... ...and it's now 1 full storey high and rising... ...so what do we do now? OPEN THE DOORS! OPEN THE DOORS! It may not have worked, but I bet it was great fun! More detail on this incident is available here.