The Fall of Pan Am 103: Inside the Lockerbie Investigation resulted from Duffy and Emerson’s 15-month investigation into the December 21, 1988 airplane crash in Scotland. The explosion and crash killed 259 persons. The book describes the efforts of 10,000 law enforcement officials from the FBA, CIA, Scotland Yard, Scottish police, and West Germany’s BKA. The authors said this comprised the largest international terrorism investigation ever undertaken.