The blistering loss and 6-10 record were too much for the franchise's most successful coach to keep his job.
NFL Media Insider Ian Rapoport reported earlier Sunday that a win against Carolina might not have even been enough to save Smith's job.
The embarrassing loss made owner Arthur Blank's decision easy.
Rapoport also reported that the Falcons retained a search firm in the event they also fire general manager Thomas Dimitroff, per a source close to the situation. NFL Media's Albert Breer reported Monday that the sense is that Dimitroff's job is safe. However, Blank plans on shaking up the organizational structure, Breer reported, per a source.
Smith ends his time in Atlanta with a 66-46 record.