I always think to the towers that fell and killed 12 (?) people.
Jesus said, "Do you think any of those the tower fell on were worse sinners? I tell you no!"
I also think of some of the Apostles "infirmities" Paul in perticular who prayed 3 times for the Lord to take it away, and was told, "My grace is sufficent for you." This is the same man that through Christ healed the sick, the dying, and the crippled. Who also told Timothy (I think it was Tim) to have a little wine because of his health. Think about that one.
We all have a time to go. It's not a matter of faith how long you live, or what you die of. Both may have had the same faith, but, also, if you pray in faith, you pray, "YOUR will be done!"
As for the rest, who aren't dying, but just hurt or crippled. It's a fact that through our weakness the Lord is strong. Sometimes we have infirmities just to help us get closer to the Lord. If I have something wrong with me that makes me a better person, and helps me depend on the Lord, Why would God want to get rid of that?