An official document from the White House was found recently at the National Archives in Washington, D.C. It was written by Bill Safire on July 18, 1969, and was written for President Richard Nixon to address the nation in the event Apollo 11 failed, and Astronauts Neil Armstrong and Edwin Aldrin could not be recovered from the lunar surface. This historic memo was simply titled "In Event of Moon Disaster". Below are scans of the document, which was two pages in length. It also included instructions on what the President should do before the announcment and instructions on what the last communications to the astronauts should be.
PAGE ONE OF "IN EVENT OF MOON DISASTER":
PAGE TWO OF "IN EVENT OF MOON DISASTER":