Being a devil's advocate:
How do people actually establish the cause of these illnesses when there is no toxicological evidence found (at least so far)? Without establishing the cause, how do they hold any organisation accountable for their losses?
What if it turns out to be a mass hysteria?
I have just been speaking to someone who has been in the middle of a bunch of people having mass hysteria and he thought that this terminal incident might possibly have been another case of it, hence this devil's advocate of a question.