From The Writer's Almanac for Thursday, November 17th, 2005:
It was on this day in 1968 that NBC interrupted its coverage of a football game between the Oakland Raiders and the New York Jets with one minute remaining in order to show the scheduled movie Heidi, about an orphaned girl who goes to live with her grandfather in the Swiss Alps.
In the last minute of the game, the Raiders scored two touchdowns, coming from behind to win the game 43 to 32. Football fans were enraged. So many people called to complain that the NBC's telephone switchboard in New York City blew 26 fuses.
It was that game, and the storm of protest by fans, that forced TV executives to realize how passionate the audience for football really was. Two years later, networks began showing football on Monday nights as well. And because of that game, the NFL now has a contract with the networks that all football games will be shown until their completion.