Baruch dayan emes
I just want to say that of course this has already been said above, but no one does know hashems plans, and they clearly are what they are for a reason! I can definitely say from personal experience that it isnt so easy to figure out why hashem did something,but you have to realize that in the end it was what had to happen, it could be for millions of reasons.
****Also a very important point I want to make is many times everyone is very helpful and caring, and making sure they are there for the family during shiva, which I want to make a point that this is a wonderful wonderful thing but then a few weeks or months or even years later this same family that still had the same tragedy happen to them doesnt have as much support and have people there for them! (not always true) I just want to say that this means so much to a family who has gone through a difficult situation to constantly have someone there for them, and not just when it first happened.