Practical illustrations of risks due to lightning along with explanation of how the damage occurs are hard to come by. This involves animals, not people, and thus may be easier to show to your boys. Plus, the explanation of the physics behind a strike (comparing why four footed species are likely to suffer more harm than two-footed) might help scouts understand our strategy of squatting in a broad circle if we can't find shelter.
http://www.nytimes.com/2016/08/31/science/lightning-strike-dead-reindeer.html