From ESPN.com:

NEW YORK -- George Steinbrenner, who rebuilt the New York Yankees into a sports empire with a mix of bluster and big bucks that polarized fans all across America, died Tuesday. He had just celebrated his 80th birthday July 4.

Steinbrenner had a heart attack, was taken to St. Joseph's Hospital in Tampa, Fla., and died at about 6:30 a.m. ET, according to multiple reports.

"It is with profound sadness that the family of George M. Steinbrenner III announces his passing. He passed away this morning in Tampa, Fla., at age 80," the Steinbrenner family said in a statement.

"He was an incredible and charitable man. First and foremost he was devoted to his entire family -- his beloved wife, Joan; his sisters, Susan Norpell and Judy Kamm, his children, Hank, Jennifer Jessica and Hal; and all of his grandchildren.

"He was a visionary and a giant in the world of sports. He took a great but struggling franchise and turned it into a champion again."

The Steinbrenner family said that funeral arrangements will be private, however details about an additional public service will be announced at a later date.

His death was the second in three days to rock the Yankees. Bob Sheppard, the team's revered public address announcer from 1951-07, died Sunday at 99.

For more than 30 years, Steinbrenner lived up to his billing as "the Boss," a nickname he earned and clearly enjoyed as he ruled with an iron fist.

He was known for feuds, clashing with Yankees great Yogi Berra and hiring manager Billy Martin five times while repeatedly clashing with him. But as his health declined, Steinbrenner let sons Hal and Hank run more of the family business.

Steinbrenner was in fragile health for years, resulting in fewer public appearances and pronouncements. Yet dressed in his trademark navy blue blazer and white turtleneck, he was the model of success: The Yankees won seven World Series titles and 11 American League pennants after his reign began in 1973.

He appeared at the new Yankee Stadium just four times: for the opener in April 2009, for the first two games of last year's World Series and for this year's homer opener, when captain Derek Jeter and manager Joe Girardi went to his suite and personally delivered his seventh World Series ring.

"He was very emotional," said Hal Steinbrenner, his father's successor as managing general partner.

Till the end, Steinbrenner demanded championships. He barbed Joe Torre during the 2007 AL playoffs, then let the popular manager leave after another loss in the opening round. The team responded last year by winning another title.

Steinbrenner had fainted at a memorial service for NFL star Otto Graham in 2003, appeared weak in 2006 at the groundbreaking for the new Yankee Stadium and later became ill while watching his granddaughter in a college play.

In recent times, Steinbrenner let sons Hal and Hank run more of the family business. Still, the former Big Ten football coach took umbrage when others questioned his fitness.

"No, I did not have a stroke. I am not ill. I work out daily," Steinbrenner said in 2006. "I'd like to see people who are saying that to come down here and do the workout that I do."

When Steinbrenner headed a group that bought the team on Jan. 3, 1973, he promised absentee ownership. But it didn't turn out that way.

Steinbrenner not only clashed with Berra for more than a decade but paid to dig up dirt on Dave Winfield, deriding the future Hall of Famer as "Mr. May" in 1985 after poor performances. Berra's wife, Carmen, said Tuesday her husband was at a golf event in Pennsylvania and was expected to comment later in the day.

While he liked to appear stern, Steinbrenner could poke fun at himself. He hosted "Saturday Night Live," clowned with Martin in a commercial and chuckled at his impersonation on "Seinfeld."

He gave millions to charity, often with one stipulation, that no one be told who made the donation.

The Yankees paid off for him, too, with their value increasing more than 100-fold from the $8.7 million net price his group paid in January 1973. He freely spent his money, shelling out huge amounts for Jeter, Reggie Jackson, Alex Rodriguez, Torre and others in hopes of yet another title.

"Winning is the most important thing in my life, after breathing," Steinbrenner was fond of saying. "Breathing first, winning next."

All along, he envisioned himself as a true Yankee Doodle Dandy. It was fitting: George Michael Steinbrenner III was born on the Fourth of July, in 1930.

Added up, he joined the likes of Al Davis, Charlie O. Finley, Bill Veeck, George Halas, Jack Kent Cooke and Jerry Jones as the most recognized team owners in history.

Steinbrenner's sporting interests extended beyond baseball.

He was an assistant football coach at Northwestern and Purdue in the 1950s and was part of the group that bought the Cleveland Pipers of the American Basketball League in the 1960s.

He was a vice president of the U.S. Olympic Committee from 1989-96 and entered six horses in the Kentucky Derby, failing to win with Steve's Friend (1977), Eternal Prince (1985), Diligence (1996), Concerto (1997), Blue Burner (2002) and the 2005 favorite, Bellamy Road.

To many, though, the Yankees and Steinbrenner were synonymous.

His fans applauded his win-at-all-costs style. His detractors blamed him for spiraling salaries and wrecking baseball's competitive balance.

Steinbrenner never managed a game, as Ted Turner once did when he owned the Atlanta Braves, but he controlled everything else. When he thought the club's parking lot was too crowded, Steinbrenner stood on the pavement -- albeit behind a van, out of sight -- and had a guard personally check every driver's credential.

Steinbrenner made no apologies for bombast and behavior, even when it cost him dearly.

He served two long suspensions: He was banned for 2½ years for paying self-described gambler Howie Spira to dig up negative information about Winfield, and for 15 months following a guilty plea in federal court for conspiring to make illegal campaign contributions during the Watergate era.

"I haven't always done a good job, and I haven't always been successful," Steinbrenner said in 2005. "But I know that I have tried."

Editor's Notes:
While I've never been a die hard Yankees fan, I still hold great respect for everything George did for that team and the city of New York.  The Yankees have become synonymous with championships through the late 90s and into the new millennium.  My deepest sympathies and condolences go out to the Steinbrenner family, the Yankee organization, the city of New York, and the millions of Yankee/baseball/sporting fans worldwide.  You will be missed, George, whole-heartedly.