I totally understand how you feel! No matter how much you know, no matter how much people tell you its not your fault, you still feel like it is....I know, I'm the same way. I can tell your a lot like me, in the sense that you take everything on your shoulders, and always think what if...or why didn't I...
And now its easy for me to say because I'm not emotionally attached at this point...but its true...you did EVERYTHING you could these things happen, its sucks, but all you can do is know that you made all the right calls, and did all that you could.
And as far as being jinxed or unlucky....I truely find that sometimes things like this come in packs...you get a bunch of sh*t that just hits the fan, then as quickly as it came, it quiets down....wierd how things work like that.
Hang in their!