Bad things don't happen to people just because they're sinners:

(Luke 13:1-5 NIV) Now there were some present at that time who told Jesus about the Galileans whose blood Pilate had mixed with their sacrifices. {2} Jesus answered, "Do you think that these Galileans were worse sinners than all the other Galileans because they suffered this way? {3} I tell you, no! But unless you repent, you too will all perish. {4} Or those eighteen who died when the tower in Siloam fell on them--do you think they were more guilty than all the others living in Jerusalem? {5} I tell you, no! But unless you repent, you too will all perish."

The real question is why bad things happen to those who are saved and follow Christ. I believe that those things happen to make people grow. There seems to be a lot of health issues with pastors and their families. Other times I think they serve as an example of remaining faithful to God despite trials and tragedy.