So these guys loaded a special "explosive containment vessel" with about 250 commercial grade illegal fireworks. Then they added 10lbs of their own explosives to initiate the explosion. They said the container is rated for 15lbs of explosives, well under max, right?.

LAPD Chief says they don't know why it failed. They followed all protocols!!!

Someone apparently forgot to figure in the weight of the illegal fireworks into their equation. I think they may have surpassed the 15lb max just a wee bit huh?