"Exasperated, Murphy made a snide comment that if there were two ways to do do something and one could result in catastrophe, someone would invariably choose to do it the catastrophic way. His colleagues overheard him and began repeating the adage. Before long, 'Murphy's Law' caught on and became widely quoted. It was added to Webster's Dictionary in 1958."
[In September 2004, Genesis, a NASA space probe designed by Lockheed Martin (the firm behind the warped Hubble space telescope and the Mars Climate Orbiter which, in 1999, did not so much orbit Mars as slam into it), plummeted to Earth when its parachute failed to open. The problem? The switches designed to trigger its release were installed backwards.]