Yeah, that's one of the weird things for me, personally, when you start talking money of that amount. I can feed, house, and cloth myself for the rest of my life on a single million, with enough left over to probably do the same thing for two or three of my family members. That 17.8 will (can, at least) do the same thing for the immediate survivors, their family, and their descendants for several generations, while having enough left over to do the same thing for probably a couple other full families.
I'm not, and wouldn't, say anything on that particular case. All I can really say is I don't see how anyone can really need, much less use -- without being horrendously inefficient or going into a large scale business -- more than a million dollars. It's one of the reasons that the wealthy culture in America (and I'm counting any and every one with more than about a 70k a year income in that) is almost completely incomprehensible to me. I've calculated it out; I can eat comfortably for multiple decades on the price of some of the lower end luxury cars. I can feed several other people, healthily, on the same budget, for only a slightly shorter amount of time. There's just... there's just a point, after which, more money just doesn't do anything meaningful, unless it's going to help other people. There's nothing you can really do at that point that can improve your life, on a personal level, more than you'd be perfectly capable of doing with less.
I guess the point to me would be giving the victims however much money, even astronomically more than they'll receive, wouldn't trouble me in the least if they turned the excess into good works. Similarly, giving them enough to live well for the rest of their life (1 mill a head, as vulgar a way of putting it as that is) and then spreading the rest among appropriate charities would sit best with me.
Perhaps as Fenrir notes, there's a point where 'more money' isn't going to have any meaningful impact. Ten million or twenty million or twenty billion, it's just... there's a cut off point, where it stops mattering to anyone sane. It's not that it's too much, or too little, it's just that it's... tangential, I guess. There's not a price you can put on life according to traditional morality, so trying to recompense lost life with money is... missing the point, I guess. Trying to feed someone with steel. Steel makes makes pretty useful building material, but it doesn't do much as food goes.
What would more do? Assuage the moral guilt of the people that caused the incident? Somehow set something right? I'm not saying it wouldn't be just have given more, I'm just saying I don't see/understand how it would impact the tragedy.
I would see justice, personally, as giving the lives of the ones responsible for the crash to the injured family. That's tangential to the question I present above, though.