In the 1960s, tapes were expensive and broadcasters had precious little storage space, so they frequently “wiped” (erased) tapes after a few viewings in order to use them again. On January 15, 1967, the New England Patriots played the New York Giants in Super Bowl I. The game was broadcast on both CBS and NBC and of course, both stations filmed it. (Super Bowl I was, by the way, the only Super Bowl to be filmed by two affiliates, due to the fact that CBS owned the airing rights for NFL games and NBC owned the rights for AFL games.) However, neither CBS nor NBC saw any use in keeping the footage of the game, so both companies wiped their tapes. A popular rumor is that the tapes were reused to record soap operas.
The National Football League had their own film crew, NFL films, who did shoot a substantial part of the game, although there is of course no commentary and they have never released what they have in its entirety. Amazingly, although color footage of Super Bowl III exists, Super Bowl II was also erased, only half of Super IV exists, and no one knows what has happened to the footage from Super Bowl V. A permanent archive for game footage was finally created starting with Super Bowl VI.