Why do bad things happen to good people?

I've been reflecting a lot over the past few days as to why bad things happen to good people.  I received a call from my mom on Thursday that my half-brother came home from work on Wednesday and found his girlfriend dead on the bathroom floor.  The autopsy reported that she died from a massive epileptic (sp?) seisure. I didn't know her too well, but what I did know is that she was a real nice and bubbly person.  However, I'm really concerned about my half-brother now that she is gone. He's had kind of a rough life.  He wasn't a good student in high school...so never went to college.  He got married young to a women who made his life a living hell once they were divorced (well his life with her wasn't too good even before the divorce).  He never made enough money for her nor had a job that she thought was good enough (he was a truck driver). As part of the divorce  settlement, he lost the house he had put so much effort in making a home with their three kids.  Then his ex-wife continually made his life miserable...demanding more child support, turning teh kids on him, etc.  The company he worked for for many years went out of business and he was forced to "start over" in terms of salary, benefits, seniority, etc. Obviously "jaded" about realtionships with women after the experience with his ex-wife, he met a women that would eventually make him happy.  That was 3.5 years ago and my mom says that she had never seen him so happy.  When she was diagnosed with breast cancer a couple of years ago, he stood by her side and celebrated together as she beat cancer and her heath was restored.  Now her tragic and untimely death...at 45 years of age.  Apparently there were no warnings.  She hadn't had a seizure in the 3.5 years they had been together. My half-brother is a great guy.  His kids have realized the lies of his ex-wife and cherish their realtionship with their dad.  He's a great friend to many and a hard worker.  Now, he's 54 and has lost the one person in this life who finally made him happy.  She, of course, was a wonderful and didn;t deserve to die at such an early age. I know God has a plan for all of us...and most times we don't understand what those plans are.  However, it is so hard to see something like this happen and wonder why?  A good women is dead and a good man is left alone.