INDIANAPOLIS -- Jim Caldwell endured everything thrown at him during his first two seasons as the Colts' coach -- replacing a friend, constant criticism, even fighting through a huge rash of injuries.

He couldn't survive the loss of Peyton Manning.

Caldwell became the Colts' third high-profile dismissal in an offseason purge, getting fired Tuesday after producing the franchise's worst record in two decades.

"This is obviously a big transitional time for us, and I know we're excited moving forward and it's hard when you say goodbyes to some people," team owner Jim Irsay said. "But it's part of the business."

In Indianapolis, it's been anything but business as usual.

The day after they finished 2-14 and locked up the No. 1 overall draft pick, Irsay fired team vice chairman Bill Polian, the architect of the Colts' success, and his son, Chris, the hand-picked general manager.

A nine-day search prompted Irsay to hire 39-year-old Ryan Grigson as the replacement last Wednesday.

Since then, Irsay and his new GM have been meeting almost non-stop, debating what tack the team needed to take next -- bringing in new assistants to fix the problems or making wholesale changes?

Things were so clouded Monday that Caldwell even met with former Rams coach Steve Spagnuolo about possibly becoming the Colts' new defensive coordinator. By Tuesday morning, the conventional wisdom in Indy and around league circles was that Caldwell would return.

A few hours later, everything changed as suddenly as the Colts' 2011 fortunes. Irsay said he informed Caldwell of the decision shortly before the team confirmed the move.

On Twitter, Irsay called Tuesday a "tough day."

"Tough day saying goodbye 2 my friend n my coach..there's less than 75 living men that can say they walked out on SupBowl Sunday as an NFL HC," Irsay wrote.