Aw, hell.... I'm sorry. My condolences to you and your wife, and to your friend's family and loved ones.
Death is certainly no respecter of persons. A buddy of mine, a few years back, died in his sleep of pneumonia. When I was in the Army, we were called to the gym to pick up a fella' who was in top physical condition. He was playing basketball and leapt for a rebound. He was dead before he hit the floor, from a massive heart attack. No one could have predicted such a thing.