January 5, 2023 had something rare occur in football history. The very warranted cancelation of an NFL contest. On January 2, 2023, during a Monday Night Football game between the Buffalo Bills and the Cincinnati Bengals, Bill Safety Damar Hamlin collapsed after tackling Bengals wide receiver Tee Higgins. Hamlin stood up after the first-quarter tackle and then collapsed in what was later learned to be an episode of cardiac arrest for the 24-year-old professional athlete. Medical personnel rushed onto the field and almost immediately provided CPR. The game officials, the NFL and NFLPA, and both teams made a great decision to suspend the playing of the rest of the game. It was a pivotal game in the realm of AFC playoff seedings, but in the overall picture, it was inconsequential to the life emergency of Mr. Hamlin.
Ironically the Nielsen rating folks said that the "ESPN MNF broadcast had an average of 23,788,000 viewers across ABC, ESPN, and ESPN2 from approximately 8:30 pm to 10:09 pm. That surge makes it the most-watched "Monday Night Football" broadcast since the NFL moved the series to ESPN in 2006, surpassing the previous 21.8 million viewers for a Packers-Vikings game in 2009." according to a CNN.com.
On January 5, 2023, the NFL did something it had not done since 1935, cancel a regular season League game. That game scheduled for November 17, 1935, between the Philadelphia Eagles and the Boston Redskins was due to heavy rain and snow that made the playing surface of Shibe Field unplayable.

Redskins and Eagles Kept Idle
Redskins and Eagles Kept Idle 18 Nov 1935, Mon The Boston Globe (Boston, Massachusetts) Newspapers.com

Preseason games, strike year contests, and COVID-19 games have been canceled days before their scheduled date, but same-day cancellations are infrequent for the NFL.

We wish Damar Hamlin best wishes and a speedy full-recovery!