INDIANAPOLIS -- Bill Polian thought the Indianapolis Colts needed a simpler defense. Jim Mora believed the Colts needed to get better players, not fire defensive coordinator Vic Fangio.

So, the Colts made a choice on Tuesday. They fired Mora.

"My feeling was that we needed a change in defensive approach," Polian said. "Not because Vic isn't a good coach. He is. Not because his system is not good. It is. I just think with the young players we have, we need a different approach."

Mora could have kept his job, if he'd agreed to fire Fangio and agreed to work within certain conditions. But he refused, even though Fangio told Mora not to worry and Mora said Fangio had been offered the Houston Texans' defensive coordinator job.

But Mora, who defended Fangio after his final game as Colts coach, didn't think Fangio was the problem.

"Vic said, 'If it comes down to you or me, don't sacrifice your position for me,' " Mora said. "It came down to, in my mind, what was right and what was wrong."

Fangio, reached at his home by telephone, declined comment Tuesday night.

Just about everything went wrong for the Colts this season.

Indianapolis was considered a preseason Super Bowl contender, but finished 6-10. The Colts were just 3-5 at home and had losing streaks of three and five games.

While some blame could be placed on the offense, which had a conference-high 38 giveaways, much of the blame was placed on a defense that finished 29th overall and last in points allowed.

Mora defended the numbers.

"Our guys fought hard, played hard and busted their tails and I like our guys," Mora said. "But you take an inferior defense and add that horrible field position they had and the turnovers and it makes it even worse. We weren't good enough to overcome that."

Polian acknowledged that he was also at fault for not providing Mora and Fangio with more impact players, but said he believes the system was too complex for Indianapolis' young players.

The Colts had six first-time starters on defense this year and Polian said Tuesday there could be four or five more new starters next season, some coming out of the NFL draft.

Mora said Fangio wasn't the only assistant Polian asked him to fire, but would not elaborate on who else was involved. Polian said the assistants are under contract and will be "retained," for now.

After the firing, Mora thanked many within the organization -- team owner Jim Irsay for the opportunity to coach the Colts, the players for their effort and everyone from vice presidents to custodians for their support.

However, he did not mention Polian or characterize their relationship.

"I'm not going to get into that," he said.

The search for Mora's replacement begins immediately. Polian said he would begin compiling a list of candidates Tuesday night and he would share that list with Irsay before conducting interviews.

While Polian refused to identify specific candidates, one name he was asked about was LSU coach Nick Saban, who recently agreed to a contract extension with LSU after winning the SEC title this season. He interviewed for the Colts job when Mora was hired.

Mora leaves after compiling a 32-32 record in four seasons with the Colts. He also was 0-2 the playoffs.

But this past season was his most tumultuous.

The Colts struggled on the field with injuries, including a season-ending knee injury to two-time NFL rushing champ Edgerrin James and a knee injury that kept linebacker Mike Peterson, the Colts' best defender, out of seven of the last eight games.

Off the field, there was a public feud between Mora and two-time Pro Bowl quarterback Peyton Manning. There were also murmurs that James was unhappy in Indianapolis, and Polian's 20-minute rant on a local radio station as he defended the team's diagnosis on James' injury.

Mora, who is 18th on the career list with 125 victories during his 15-year NFL career, led the Colts from back-to-back 3-13 seasons to the AFC East title in 1999 with a 13-3 record and the greatest one-year turnaround in NFL history. The Colts were 10-6 the next year, the first time the Colts posted double-digit wins in back-to-back seasons since 1976-77.

Before joining the Colts, Mora was coach for 10½ seasons in New Orleans, where he went 93-74 and guided the Saints to their first four playoff appearances. Mora never won a playoff game there, though.

Mora also was coach of the Philadelphia-Baltimore Stars of the USFL. He led the Stars to three straight league title games, winning championships in 1984 and '85.