Week 18 of the 2021 NFL season concludes on Sunday, which means for non-playoff teams, changes are usually made the following day. In what many refer to as "Black Monday," NFL teams fire head coaches, coordinators and general managers alike. Usually in an effort to turn over a new leaf for their organization.The coaching dismissals began Sunday morning when the Denver Broncos parted ways with head coach Vic Fangio after his team's disappointing 7-10 finish this season.On monday morning the firing continued. Minnesota Vikings head coach Mike Zimmer, Chicago Bears head coach Matt Nagy and, most shocking of the day, Miami Dolphins head coach Brian Flores were all shown the door.NFL fans immediately took to Twitter to voice their joy, displeasure and general shock at some of the decisions that were made regarding the now former NFL head coaches.NFL fans take to Twitter to voice their opinions on "Black Monday"The first dismissal of the day was Minnesota Vikings head coach Mike Zimmer along with general manager Rick Spielman. Zimmer was hired as their head coach back in 2014 whereas Spielman had been with the Vikings organization since 2006 and assumed the role of general manager in 2012.Zimmer had been non-committal as of late when asked about whether he would be retained, but did acknowledge recently that he was "in the hot seat."Ari Meirov@MySportsUpdateThe #Vikings have also fired HC Mike Zimmer after eight seasons with the team, as @TomPelissero said. His head coaching career in Minnesota ends with a 72–56–1 record and three playoff appearances.9:09 AM · Jan 10, 20221872227The #Vikings have also fired HC Mike Zimmer after eight seasons with the team, as @TomPelissero said. His head coaching career in Minnesota ends with a 72–56–1 record and three playoff appearances.The Miami Dolphins' firing of head coach Brian Flores was one of the most shocking dismissals of the morning. Flores and the Dolphins had won eight of their last nine games, which included beating the New England Patriots on Sunday afternoon.Emmanuel Acho@EmmanuelAchoThe firing of Brian Flores is ridiculous at best and incompetent at worst. Flores won 19 games over 2 years in Miami (the Dolphins haven’t done that since 03) with a QB that is hurt as often as he’s healthy. He finished the year going 8-1. This move is what bad franchises do.10:02 AM · Jan 10, 202279421103The firing of Brian Flores is ridiculous at best and incompetent at worst. Flores won 19 games over 2 years in Miami (the Dolphins haven’t done that since 03) with a QB that is hurt as often as he’s healthy. He finished the year going 8-1. This move is what bad franchises do.Meanwhile in Chicago, the Bears fired head coach Matt Nagy as well as general manager Ryan Pace, a move that seemed to come as a relief to many. In recent times Bears fans have been very vocal about their desire to see Nagy being let go as head coach. While the additional firing of Pace is apparently everything some Bears fans could have hoped for and more.Barstool Chicago@barstoolchicagoMATT NAGY AND RYAN PACE HAVE BOTH BEEN FIRED9:56 AM · Jan 10, 20223388483MATT NAGY AND RYAN PACE HAVE BOTH BEEN FIRED https://t.co/fOFRRE9ceoTom Pelissero@TomPelisseroMore from @gmfb on the blowup in Chicago with Matt Nagy and Ryan Pace both out, as well as the firing of Brian Flores in Miami. @nflnetwork9:43 AM · Jan 10, 202233968More from @gmfb on the blowup in Chicago with Matt Nagy and Ryan Pace both out, as well as the firing of Brian Flores in Miami. @nflnetwork https://t.co/Tj7PGUjTxTOne Bears fan immediately brought up University of Michigan head coach Jim Harbaugh as a potential replacement for Nagy in Chicago. Harbaugh was drafted by the Chicago Bears in 1987 and was their quarterback until 1993.Big Cat (1-0 in GOTY bets)@BarstoolBigCatNow that Matt Nagy is officially fired. Sometimes you’ve gotta go back, to actually move forward9:25 AM · Jan 10, 20225888523Now that Matt Nagy is officially fired. Sometimes you’ve gotta go back, to actually move forward https://t.co/lhtfqi49DAOne twitter account even went as far as referencing "Seinfeld" character, George Constanza. Who once said that he could be a coach in the NFL.This Podcast is Making Me Thirsty - Seinfeld@ThisThirstyBlack Monday tough on a lot of NFL Coaches"I'm telling you, I can coach in the NFL. It's not that hard." - George Costanza10:02 AM · Jan 10, 2022163Black Monday tough on a lot of NFL Coaches"I'm telling you, I can coach in the NFL. It's not that hard." - George Costanza https://t.co/ZqVvlqycVQSome people took this chance to remind NFL fans of the human element that comes with "Black Monday". The firing of coaches and general managers will undoubtedly mean that their families are affected.Stephanie Rivera@CoachRiv2I really hate "Black Monday" in the NFL. Prayers up for the families dealing with this very public transition in your lives. Good luck on your next team!9:44 AM · Jan 10, 202224524I really hate "Black Monday" in the NFL. Prayers up for the families dealing with this very public transition in your lives. Good luck on your next team!Jen Mueller@JenTalksSportsJust a reminder during "firing season" and "Black Monday" in the NFL - you're talking about human beings not characters in a TV show. The real NFL is not a video game. Remember to show some class, or heck even empathy, when talking about people who lose their jobs.11:15 AM · Jan 9, 20221814124Just a reminder during "firing season" and "Black Monday" in the NFL - you're talking about human beings not characters in a TV show. The real NFL is not a video game. Remember to show some class, or heck even empathy, when talking about people who lose their jobs.Will there be more head coaching vacancies as the day moves on? That remains to be seen. Some head coaches around the league could be given another opportunity next season to prove they belong in the league.