(CNN) -- William Clay Ford -- grandson of automaker Henry Ford and the figurative father of the Detroit Lions' NFL franchise -- died Sunday morning after battling pneumonia.
He was 88.
The Ford Motor Company -- for which Ford served for 57 years as an employee and board member -- said that Ford died at his home. William Clay Ford Jr., the company's former president and current executive chairman, remembered his father as a "great business leader and humanitarian" as well as "a wonderful family man."
The news about Ford hit especially hard among those associated with the Lions, which he became president of in 1961 and purchased two years later. He was the team's chairman at the time of his death.
"No owner loved his team more than Mr. Ford loved the Lions," Tom Lewand, team president, said.
Lions' greats -- past and present -- weighed in on Twitter. Star wide receiver Calvin Johnson called the news a "great loss to the Lions family."
"Mr. Ford was a visionary that will be missed by all," said Hall of Fame former running back Barry Sanders.
He leaves behind Martha Firestone Ford, to whom he was married for 66 years, three daughters and his one son, 14 grandchildren and two great-grandchildren.
CNN's Jill Martin contributed to this report.