"Something?". Having them inhale oil or dirt will do it. Pneumonia is usually caused by a bacteria that's just everywhere (though usually on the skin), that's t

"Something?". Having them inhale oil or dirt will do it. Pneumonia is usually caused by a bacteria that's just everywhere (though usually on the skin), that's too simple. If it starts growing in your lungs, you can try antibiotics. If that doesn't work, well, nice knowing you. We are surrounded by lethal bacteria. That humans survive depends on the immune system having a 100% success rate preventing bacteria from forming even a small colony in the lungs (and several other places, like the teeth, where infections can rapidly and surprisingly turn deadly) This is why people cough so extremely hard when inhaling solid or liquid stuff in their windpipes. Also this happens all the time. That someone dies from pneumonia is not uncommon (though for oil it's usually someone who manages to spray themselves with aerosolized oil at work). So even if an autopsy found a few specs of dirt in the lungs, and even if they actually trace that to be the cause, that's not extremely suspicious. (Plus why would they check? Obviously with a pneumonia patient you know the cause of death)