A large two-engine train was crossing America. After they had gone some distance one of the engines broke down. "No problem," the engineer thought, and carried on at half power. Farther on down the line, the other engine broke down, and the train came to a standstill. The engineer decided he should inform the passengers about why the train had stopped, and made the following announcement: "Ladies and gentlemen, I have some good news and some bad news. The bad news is that both engines have failed, and we will be stuck here for some time. The good news is that you decided to take the train and not fly."