Basically, incompetence. Happens everywhere, but especially in places where people just don't care much about anything (I am from such a country). People who s

Basically, incompetence. Happens everywhere, but especially in places where people just don't care much about anything (I am from such a country). People who stored the fireworks didn't know about the ammonium nitrate, not their problem. Welders didn't know anything. They just came to do their job. Safety standards are just not a thing in many places. It's even considered a joke among many workers - you gotta work fast, not care about your ears/hands/eyes/cars/surroundings etc. It's sad. People managing the warehouse also didn't know about what's going on, and likely didn't care enough to find out.