Team owner Arthur Blank said more changes could come. He said general manager Thomas Dimitroff will be part of the search for a new coach, but then could have his status reviewed.
"We want that (search) process to play out," Blank said. "It will help us determine if we'll make any other changes to the structure of any other parts. ... Hiring the coach is the first move but may not be the only move."
Blank said firing Smith was "the most difficult decision I've had to make." Blank said he met with Smith on Monday, and the meeting ended with an exchange of warm emotions.
"The last thing he said was 'I love you' and I said the same thing," Blank said.
Dimitroff and team president Rich McKay attended Monday's news conference with Blank.
Atlanta had a 66-46 regular-season record with Smith and won two NFC South titles. But this season ended at 6-10.
"It's a fact Smitty was the most successful coach in the history of the Falcons franchise," Blank said.
Blank said the decision was not based on one game or even one season.
The Falcons would have won the NFC South and hosted a wild-card playoff game by beating Carolina on Sunday. Instead, it was an ugly end to the season.
Blank left open the possibility a playoff berth might have saved Smith's job.
"I had not made a decision if we had won what our next step was going to be," Blank said.
Ultimately, Blank decided Smith was not the right coach to take the Falcons to the Super Bowl.
"Can that individual take you to the next level?" Blank said of his appraisal of Smith. "If your answer is no in your heart or hearts, you have to put away your personal feelings."
Blank said he will be involved in the search for a new coach that would begin by submitting formal requests to interview candidates currently coaching other teams. He said he had no timetable for hiring a new coach.
Smith joined the Falcons with Dimitroff in 2008. Quarterback Matt Ryan was the new management team's first draft pick, and the three combined for early success with five straight winning seasons.
Before Smith was hired, the Falcons never had back-to-back winning seasons. He immediately raised expectations with an 11-5 finish in his first season. The Falcons won 10 or more games in four seasons under Smith, including 13-3 finishes in 2010 and 2012. Smith reached 50 wins in only 71 games, the third-fastest pace since the 1970 AFL-NFL merger.
Smith, however, had a 1-4 record in the playoffs. Following a trip to the NFC championship game in 2012, the Falcons have fallen to 10-22 the past two seasons.
Dimitroff has been criticized for draft and free-agent decisions, including the inability to improve the team's pass rush.
"I know I have made mistakes and I'm going to be scrutinized for it," Dimitroff said.
Dimitroff and McKay defended the talent on the roster. Dimitroff said personnel decisions were made in a "very collaborative process" with Smith.
Before he was hired by the Falcons, Smith was the defensive co-ordinator for the Jacksonville Jaguars from 2003-07. He was a defensive assistant with Baltimore from 1999-2000.
Blank said plans to move into a new stadium for the 2017 season were not a factor in the decision to make a coaching change.
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