Dumb accident.

Explosions on this scale, thanks to idiots storing shit where and how they shouldn't, happen every couple of years.

If you type 'explosion in fireworks' you'll come up with multiple fireworks factories/warehouses blowing up. You'll find other explosions involving fertiliser plants, refineries and random factories.

For example, 2016 in Tianjin: an overheated container of dry nitrocellulose blew up, took the factory with it and about 160 died. Left a massive crater.

People are idiots. Always assume stupidity before malice.