The brightest thing I've ever seen was a General Purpose (GP) tent full of magnesium snowshoes burn to the ground in the high Sierras. The year was 1983 and I remember it like it was yesterday. We were at least 200 yards away watching it, but it still felt like our skin was burning. It also seemed brighter than the sun. It probably started because of the M1940 Yukon Stove; they were famous for burning tents down. Like Chris, I've seen those snoeshoes laying in a fire with no results; throw in some diesel fuel and some canvas... now that's another story.
Semper Fi, George