Hey Golfers, Sports Fans And Everyone Else - Lightning Causes Thunder

Have you ever watched a college football or baseball game on TV and noticed fans sitting in the stands during a lightning delay. I always find it amusing that they stay during lightning but leave if it starts raining. A few years ago I was watching a sporting even on a major network. One of the announcers said something along the lines of  "it is thundering but we should be okay because I didn't see any lightning."