Bo Schembechler, who became one of college football's great coaches in two decades at Michigan, died Friday after taping a TV show on the eve of the Wolverines' No. 1 vs. No. 2 showdown with perennial rival Ohio State. He was 77.

"This is a tremendous shock and an irreplaceable loss," University of Michigan president Mary Sue Coleman said at a news conference at Providence Hospital in Southfield, where the coach died.

Schembechler collapsed at the studios of WXYZ-TV in the Detroit suburb and was taken by ambulance to the hospital. His death at 11:42 a.m. was confirmed by Mike Dowd, chief investigator for the medical examiner's office in Oakland County.

Police were sent to the station about 9:25 a.m. along with the city's fire department and escorted the ambulance, Southfield police spokesman John Harris said.

"The electrical part of the heart was working fine but the mechanical part was not working," said Dr. Shukri David, the head of cardiology at Providence Hospital. "The heart was sending signals to the heart muscle to contract. The muscle was not responding."

Schembechler had a heart attack on the eve of his first Rose Bowl in 1970 and another one in 1987. He had two quadruple heart-bypass operations, and doctors implanted a pacemaker to regulate his heartbeat after he became ill during a taping at WXYZ on Oct. 20.

During a news conference this week to discuss Saturday's big game, Schembechler said the device covered about half his chest and doctors still were adjusting it.

Schembechler said he did not plan to attend the game in Columbus, Ohio, and that he didn't travel to road games anymore.

"This is an extraordinary loss for college football," Ohio State coach Jim Tressel said in a statement. "Bo Schembechler touched the lives of many people and made the game of football better in every way. He will always be both a Buckeye and a Wolverine and our thoughts are with all who grieve his loss."

The seven-time Big Ten coach of the year compiled a 194-48-5 record at Michigan from 1969-89. Schembechler's record in 26 years of coaching was 234-65-8.

Schembechler's Wolverines were 11-9-1 against the Buckeyes. But fans in both states generally agree the rivalry's prime years were 1969-78, when Schembechler opposed his friend and coaching guru, Woody Hayes. Michigan prevailed in those meetings, going 5-4-1.

"It was a very personal rivalry," Earle Bruce, who succeeded Hayes as coach, once said. "And for the first and only time, it was as much about the coaches as it was about the game.

"Bo and Woody were very close because Bo played for Woody at Miami of Ohio, then coached with him at Ohio State. But their friendship was put on hold when Bo took the Michigan job because it was the protege against mentor."

In their first matchup, Schembechler's team pulled off a startling upset, winning 24-12 to deny No. 1 Ohio State its second consecutive national championship. The victory came a year after the Buckeyes embarrassed Michigan 50-14.

Thirteen of Schembechler's Michigan teams either won or shared the Big Ten championship. Fifteen of them finished in The Associated Press Top 10, with the 1985 team finishing No. 2.

Seventeen of Schembechler's 21 Michigan teams earned bowl berths. Despite a .796 regular-season winning percentage, his record in bowls was a disappointing 5-12, including 2-8 in Rose Bowls.

The mythical national championship eluded Schembechler, but he said that never bothered him.

"If you think my career has been a failure because I have never won a national title, you have another thing coming," Schembechler said a few weeks before coaching his final game. "I have never played a game for the national title. Our goals always have been to win the Big Ten title and the Rose Bowl. If we do that, then we consider it a successful season."

His last game as Wolverines coach was a 17-10 loss to Southern California in the 1990 Rose Bowl. One week later, Schembechler — who also had been serving as Michigan athletic director since July 1988 — was named president of the Detroit Tigers.

Schembechler's signature moment as athletic director probably came in March 1989, when basketball coach Bill Frieder accepted a job at Arizona State on the eve of the NCAA tournament.

An angry Schembechler declared, "A Michigan man will coach Michigan, not an Arizona State man." He refused to accept Frieder's 21-day notice and named assistant Steve Fisher as interim coach.

The Wolverines went on to win the national championship by beating Seton Hall 80-79 in overtime.

Schembechler's tenure as Tigers president was less rewarding.

Schembechler fired beloved broadcaster Ernie Harwell after the 1991 season. Harwell was brought back two years later.

Schembechler hired extra coaches for every farm team, upgraded all the facilities and introduced football-style strength and conditioning programs.

But those moves bore little fruit at the big-league level. The Tigers' last winning season was in 1993 until they advanced to the World Series this season.

Tigers owner Tom Monaghan fired Schembechler as Tigers president the day before he sold the team to Mike Ilitch in August 1992 — and 13 days before Schembechler's wife, Millie, died at age 63 of adrenal cancer. Bo Schembechler sued, claiming Monaghan had broken a contract the Domino's Pizza owner had jotted down on a napkin. They settled out of court in 1994.

Schembechler was an intense disciplinarian and his gruff persona belied his devotion to his players, both during and after their playing days in Ann Arbor.

"He preached the team from day one, and it's still being taught now," offensive guard Reggie McKenzie, who played for Schembechler from 1969-71, said when he was inducted into the College Football Hall of Fame in 2003.

McKenzie said Schembechler's iron hand almost prompted him to quit. But, he said: "I learned to beat him by doing it the right way every time, all the time. That's the attitude we had at Michigan."

While Schembechler loved coaching, he was less enamored with some other aspects of college football. In his 1989 book "Bo," co-written with Detroit Free Press sports columnist Mitch Albom, Schembechler decried drugs, sports agents and the pressures of recruiting.

"Recruiting is the worst part of college football," he wrote. "I no longer look forward to it. I can't wait until it's over. It makes me feel like a pimp."

Schembechler was born April 1, 1929 in Barberton, Ohio. He graduated in 1951 from Miami of Ohio and earned a master's degree in 1952 at Ohio State, where he served until 1953 as a graduate assistant under Hayes.

After serving in the Army, Schembechler held assistant coaching jobs at Presbyterian College in 1954 and Bowling Green in 1955, then joined Ara Parseghian's staff at Northwestern in 1958 before returning to Ohio State as an assistant to Hayes.

Schembechler was hired as head coach at Miami in 1963, winning two Mid-American Conference titles in six seasons. In 1969, he took over a Michigan program that had posted six losing seasons over the previous 11 years. He did not have a losing season at either school.

Schembechler worked as an ABC Sports football broadcaster and analyst in 1991-92 and was a popular motivational speaker for many years.

Schembechler was inducted into the Miami University Hall of Fame in 1972, the State of Michigan Sports Hall of Fame in 1989, the University of Michigan Hall of Honor in 1992, the Rose Bowl Hall of Fame in 1993 and the National Football Foundation Hall of Fame in 1993.

Bo and Millie Schembechler had one son, Glenn III. Schembechler and his second wife, Cathy, married in 1993.