Super Bowl II (partially lost live broadcast; 1968)
The second installment in the now long-running AFL-NFL Super Bowl series was played and broadcast live on radio and on the CBS television network on January 14, 1968 (and it was also the first Super Bowl to be broadcast solely by one television network, as would be the case for all subsequent Super Bowls, the very first Super Bowl was simulcast on television between CBS and NBC), with the outcome of the game seeing the Green Bay Packers triumph over the Oakland Raiders 33 to 14. As it aired such a long time ago, it had been considered lost for many years, with the only remnants of the broadcast remaining being a few photographs (the majority of which were published in the January 8, 1969 issue of Sports Illustrated), as well as the game play information that was written down during the broadcast.
It also became notable for the fact that viewers nationwide were unable to see the final few minutes of the second quarter and the first three minutes of halftime, with the exception of those watching on the WJW affiliate in Cleveland and in a number of Northeastern markets including New York City and Philadelphia. CBS blamed this on the failure of AT&T's cables that were used to deliver the broadcast across the network.
In recent years, it has been alleged that a copy was found in the vault of NFL Films and that said copy was being restored for re-release, although this claim has not been confirmed and has actually (apparently) been directly denied by an NFL Films employee. Despite this, a reconstructed copy did show up on YouTube in March 2013, using still photographs, video snippets and the (entire, unedited) audio track of the radio broadcast, although it has since been removed due to a copyright claim by the NFL. It is currently unclear as to how said audio was obtained by the uploader (LambeauPackerBacker) in the first place.