Ann Arbor, Mich. ? Ann Arbor, Mich. – 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.

“It was probably not a heart attack; it just stopped working,” Dr. Shukri David said.

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.

Former Michigan coach Bo Schembechler watches from the sidelines during a game against Illinois. Schembechler was the winningest coach in Michigan history.

“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.

Schembechler is carried off the field after a 23-6 victory against Washington in the Rose Bowl on Jan. 1, 1981.

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.

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.”

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