They have identified four types of smoke plume. But they only reconstruct three types of material in the warehouse: fireworks, tires and ammonium nitrate. Aren't they missing something?
It goes initial small fire caused by the welders -> tires -> fireworks -> ammonium nitrate. The exact cause probably won't be known because there's been no video discovered that shows that portion of the warehouse and anyone close enough to have known were likely killed in the explosion. It's not particularly important though for the purpose of the investigation because the goal was to show establish clearly that the storage was negligent so victims can seek legal redress.
It goes initial small fire caused by the welders -> tires -> fireworks -> ammonium nitrate.
Yeah, I'm not sure the "swiss cheese" model of disasters applies here. I'm not aware of any form of metaphorical cheese that could maintain it's structural integrity under the conditions present at this warehouse.
