I was watching that news about the horrible explosion in Korea. Now they are saying that it was explosives, not fuel or just fuel, that blew up. Even if explosives, and tons of it, wouldn’t they have gone off in a serial fashion - being distributed in separate rail road cars - rather than one single blast? I find it hard to believe that debris is falling more than 10 miles away from a train accident? How much and what kind of explosives would have been involved?
MSNBC reports that it was dynamite. It’s possible that it really wasn’t dynamite but they are using a familiar term. Dynamite is considered somewhat obsolete as there are plenty of less expensive explosives. For argument’s sake let’s assume it was some kind of high order explosive. You are correct that it would have gone off “serially” with the initial point setting off other explosive. If secondary explosions were set off by the shockwave note that sound is pretty zippy, about 1,100 feet per second at sea level. It would have all detonated in a small fraction of a second.
When buildings and open pit mines are blasted the charges are set off sequentially with a much longer interval. Conditions are setup so that subsequent charges will not be set off by the shockwave. Charges are set off in the ground or inside structural members so that absorbs the energy.