Interim athletic director and Nebraska great Tom Osborne announced the dismissal one day after the Cornhuskers ended the season at 5-7 following a 65-51 loss at Colorado. They squandered an 11-point halftime lead by allowing 34 consecutive points.

"As a former coach this is a role I really don't like," Osborne said at a news conference." I hate to sit in judgment of other people. I never envisioned having to do this."

Osborne said that at the end of October he told Callahan there would be a coaching change if Nebraska finished with a losing season.

The dismal results came one season after the Huskers reached the Big 12 championship game. This year also was marked by a 76-39 defeat at Kansas, the most points allowed by a Nebraska team.

The firing came one month and a day after Callahan said, "I have done an excellent job in every area." Osborne apparently thought otherwise after only the second losing season at Nebraska since 1962, both coming on Callahan's watch.

It will cost the university more than $3.1 million to buy out Callahan's contract, which was to run through the 2011 season.

The contract was signed in September before a series of the most lopsided losses in decades and the firing of athletic director Steve Pederson, who hired Callahan.

Callahan came nowhere near meeting the high standards for Nebraska football established by Osborne, who won 255 games and three national championships in 25 seasons before retiring after the 1997 season.

The names most often mentioned as possible replacements are LSU defensive coordinator Bo Pelini and University of Buffalo head coach Turner Gill.

Pelini was Nebraska's defensive coordinator in 2003 and proved extremely popular among fans, who chanted "We want Bo" after he led the Huskers to an Alamo Bowl win over Michigan State as interim head coach following the firing of Frank Solich.

Gill, a longtime assistant under Osborne and Solich, was the Huskers' quarterback in the early 1980s and a Heisman Trophy runner-up in 1983.

This season, the Huskers struggled as their defense posted some of the worst statistics in the country, their offense fell flat in the biggest games and they endured a five-game losing streak.

Callahan's four-year record was 27-22, with three of those wins coming against opponents in the division formerly known as I-AA. He was 15-18 against the Big 12, 0-7 against Top 10 opponents and 3-10 against the Top 25. He was 0-17 in games in which the Huskers trailed at halftime.

Callahan was widely acclaimed for his recruiting, and each of his classes at Nebraska were ranked high by analysts. But many of those players never lived up to their billings, and Callahan's ability to develop talent was called into question.

The Huskers won their first two games this season, but a 49-31 home loss to Southern California proved ominous, as did an embarrassingly close 41-40 home win over Ball State in which the Huskers were clearly outplayed.

"The USC game took a lot out of people," safety Ben Eisenhart said. "People put a lot into that game, everybody was excited to play and it didn't come out like we thought it would. Then we come out against Ball State the following week and it's 41-40. It's like we got knocked off track, and it was really hard for us to get back on track."

A win over Iowa State in the Big 12 opener was followed by losses of 41-6 to Missouri, 45-14 to Oklahoma State, 36-14 to Texas A&M, 28-25 to Texas and, worst of all, a 76-39 defeat at Kansas.

The Kansas fiasco marked the most points allowed by a Nebraska team. Also on Callahan's tab was the 70-10 loss at Texas Tech in 2004, the most lopsided defeat in the program's 118-year history.

At least three other candidates withdrew from consideration or declined offers before Callahan was hired Jan. 9, 2004 — 10 days after he was fired as the Oakland Raiders' coach.

Callahan won only four games with the Raiders in 2003 after taking them to the Super Bowl the year before. He replaced Solich, who had a six-year record of 58-19 and was sent packing after going 9-3 in the 2003 regular season.

Pederson said recruiting had slipped under Solich and he feared the program was "gravitating toward mediocrity."

Callahan came in with much bluster, saying he would "flip the culture." That meant dumping the triple-option offense employed by Osborne and Solich and installing the West Coast offense.

Before his first game, Callahan boasted, "We don't take what the defense gives us. We take what we want."

His 2004 team went 5-6, ending an NCAA-record 35-year bowl streak. The streak was a point of pride to Husker fans, and many were infuriated when Callahan downplayed the significance of its ending by saying, "It's one game today, it's one season. I never look back."

That comment came two weeks after Callahan insulted Oklahoma fans after a 30-3 Nebraska loss by using an expletive while calling them hillbillies.

In 2005, the Big 12 reprimanded Callahan for making a throat-slashing gesture at an official during a game against Oklahoma. Callahan denied wrongdoing.

The '05 team won three straight to finish 8-4 after losing four out of five, beating Michigan in the Alamo Bowl. That set the stage for last year, when the Huskers went 9-5 and swept all six games against the Big 12 North.