The ax has fallen on three NFL head coaches and two general managers whose underachieving teams disappointed fans and the owners who pay their big salaries.

Getting their “Black Monday” pink slips were head coaches Rex Ryan of the New York Jets, Mike Smith of the Falcons and Marc Trestman of the Chicago Bears, and GM’s John Idzik of the Jets and Phil Emery of the Bears.

Also falling victim to the revolving door of coaches was Jim Harbaugh, who agreed to part ways with the San Francisco 49ers in a departure that was long expected.

“Black Monday” comes the day after the regular season has ended and is the day when coaches are traditionally relieved of their duties and their former teams promise a fresh start in the pursuit of Super Bowl glory.

The end for Ryan and Idzik came after one of the most disappointing Jets seasons in franchise history.

With the Jets (4-12) failing to make the postseason for the fourth straight season, Team owner Woody Johnson chose to start fresh with a new coach and GM. He met with Ryan and Idzik Monday morning after "extensive thought and reflection" and informed them they would not be returning.

"Getting the Jets back on track is my top priority," Johnson said in a team statement, "and today's decisions are important steps towards achieving our goals."

Ryan was 50-52, including 4-2 in the postseason, in his six seasons with the Jets. His first few years were filled with guarantees, strong statements and two consecutive trips to the AFC title game. But, in the end, there were not enough wins to back up all the big talk.

Idzik lasted just two seasons after replacing the fired Mike Tannenbaum in 2013. He was heavily criticized this year for questionable draft and free agency decisions.

Now, the Jets will be looking for a general manager and coach for the first time since Johnson promoted Tannenbaum and hired Eric Mangini in 2006. Former NFL GM and current NFL Network analyst Charley Casserly is expected to be brought in by Johnson as a consultant to help assist the franchise in making the new hires.

The Falcons fired Smith after his second straight losing season and a 34-3 rout by the Carolina Panthers before booing fans at the Georgia Dome.

Atlanta had a 66-46 regular-season record with Smith and won two NFC South titles. But this season ended at 6-10.

"Smitty's contributions to our club, team and city over the last seven years are numerous," Falcons owner Arthur Blank said in a statement released by the team. "His accomplishments on the field made him the most successful coach in the 49-year history of the Falcons, and we are grateful for the foundation he has laid for us for the future."

The Chicago Tribune cited sources in reporting that the Bears fired Trestman and Emery after the team’s disappointing 5-11 campaign. Their final game ended with a lopsided loss to the New England Patriots, 51-23.

The Tribune said the overhaul was expected after the team sunk to their worst record in more than a decade. Seven defeats ended in double-digits.

The departure for Harbaugh came one year before his $25 million, five-year contract with the 49ers was due to expire.

The announcement he was leaving came after Sunday's 20-17 win over the Arizona Cardinals and following an 8-8 season in which San Francisco had hoped to establish some momentum in new $1.3 billion Levi's Stadium.

"It's been the time of my life," Harbaugh said. "Been a lot of great memories, great moments. ... It's been a tremendous four years, it's been a pleasure to work and serve for this organization. I feel great about what we accomplished."

He just didn't specify where exactly he is headed next, though it might wind up being one of football's most poorly kept secrets. The hints were everywhere.

Harbaugh would neither confirm nor deny that he is indeed about to accept the job at alma mater, Michigan, except to acknowledge he wouldn't be around come Monday.

The Associated Press contributed to this report.