Killing everyone inside is easy, it is the thing incendiary is actually used for in our world. Fire one in there and the flames will suck up all the oxygen in one go. The lucky ones choke.

However it won't be what Marcus will go for, I can tell you that much.

Incidentally how many signs were there that the Faunus in the camp were abused? Malnourished Faunus or something? I have a faint feeling this uprising didn't just spring up because a couple of Fang spread some rumours around.