It’s one of those stories that barely seems credible; British-led construction workers building a railway across Kenya and Uganda are picked off and eaten by a pair of unusually cunning lions. Traps are laid, but the lions manage to outwit the hunters at every stage, until in a final showdown they are defeated by a lieutenant-Colonel with a moustache and a twinkle in his eye. Some facts about the case seem to have been embellished or exaggerated (the kill-count being more like 35 than 100 for example), but the basics of the tale are apparently legit.
This is a podcast from ‘Stuff You Missed In History Class’ which discusses the case. As with all of their shows, great information, wish they would tone it down a little with the chat, and reduce the ads to something less than 30% of the show
The Wikipedia article on the case is also unusually readable and comprehensive