Hall of Fame pitcher Tom Seaver, whose nickname "The Franchise" symbolized his place as the greatest player in New York Mets History, has died at the age of 75. 

The Baseball Hall of Fame announced Seaver's passing Wednesday evening, saying Seaver died of "complications of Lewy body dementia and COVID-19."

“We are heartbroken to share that our beloved husband and father has passed away,” said his wife Nancy Seaver and daughters Sarah and Anne in a statement to the Baseball Hall of Fame, who confirmed Seaver's passing. “We send our love out to his fans, as we mourn his loss with you.”

In a statement, Mets owners Fred and Jeff Wilpon referred to Seaver as "simply the greatest Mets player of all-time, and among the best to ever play the game."

Seaver is the Mets' all time leader in wins, earned run average, strikeouts, and numerous other pitching categories. 

He pitched 20 seasons in all, and also played for the Reds, White Sox and Red Sox. He finished his career with 311 wins and 3,607 strikeouts.

His Mets career began with the biggest stroke of luck in the franchise's history. Seaver was originally drafted and signed by the Braves, but his contract was voided by MLB because at the time, teams were not allowed to sign college players while their college team's season (in Seaver's case, USC) was going on. The MLB commissioner at the time determined that any team that wanted to match the Braves' contract would be entered into a lottery to do so. The Mets were the winner of that lottery and were awarded the rights to Seaver.

Seaver was instrumental in the Mets' transformation from perennial doormat to World Series winner. The Mets lost 95 or more games in their first five seasons. Seaver joined in 1967, and the Mets went from 101 losses that year to 100 wins and a World Series victory by 1969.

Seaver - who also went by the nickname "Tom Terrific" - won his first NL Cy Young Award that year. He would go on to win the award again in 1973, when the Mets made it back to the World Series but lost to the Oakland A's, and in 1975.

Amid a contract dispute, Seaver was traded to the Cincinnati Reds in 1977, a decision that was deeply unpopular among Mets fans and, along with the team's trade of slugger Dave Kingman, was referred to as the "Midnight Massacre." Seaver did not win any World Series titles or Cy Young Awards with Cincinnati, but he did pitch his only career no-hitter as a member of the Reds, in 1978.

He made a triumphant return to the Mets in 1983, but left again after just one season after he was surprisingly claimed in MLB's Free Agent draft by the Chicago White Sox. He pitched two-and-a-half years with the White Sox, a stretch that included his 300th career win, which came against the Yankees at Yankee Stadium in 1985.

Seaver ended his career with the Boston Red Sox in 1986. He was technically a member of the Red Sox organization when Boston lost to the Mets in the 1986 World Series, but he was injured and did not pitch in the series. He attempted a comeback with the Mets in 1987, but officially retired before pitching in a competitive game with the team.

Seaver was inducted into the Baseball Hall of Fame in 1992. At the time, the percentage of the vote he received was the highest in the Hall's history.

He also had a career in broadcasting, both during and after his career. He was featured as a World Series analyst four times during his playing career. After he retired, he was a broadcaster for NBC's national baseball coverage and for Yankees games on WPIX, and then later on Mets broadcasts from 1999 to 2005, also on WPIX.

The Mets retired his number 41 in 1988. In 2019, they named the street Citi Field is located on "Seaver Way." Citi Field's official address is now 41 Seaver Way.

Seaver was not at that ceremony, however. He retired from public life in March 2019 due to dementia. 

Numerous Mets players and broadcasters posted tributes to Seaver on Twitter.

Howie Rose, who has been a part of Mets broadcasts since the 1980s, said Seaver's death was "impossible to process."

"I was privileged to know him as a boyhood idol, colleague and friend," Rose said. "Cherish the memories. Godspeed."

Dwight Gooden - who was the second pitcher to win a Cy Young Award as a Met, after Seaver - said, "Everyone knows he was a great pitcher. But he was an even greater person."

Keith Hernandez, who played with Seaver on the Mets in 1983, said, "No one will ever surpass him that wears the orange & blue."

Other Mets legends, including his teammates on the 1969 World-Series-winning team, issued statements through the team honoring Seaver.

"A great leader of our team," said Mets pitcher Jerry Koosman, a teammate on the 1969 team. "When he wasn't pitching he was always there to help the other guys on the staff. He was a true professional."

"When he joined us as a rookie, he pitched like a 35-year-old. He had a great head on his shoulders," said Mets first baseman Ed Kranepool, a teammate on the 1969 team. "We became a different a team when he walked into the locker room in 1967."

"As soon as I saw him pitch the first time, I said to myself, 'He has Hall of Fame stuff.' He just had to accumulate numbers to get to the Hall," said outfielder Ron Swoboda, a teammate on the 1969 team.

"Tom Seaver hated to lose," said catcher Jerry Grote, a teammate on the 1969 team. "In May of 1969, we had a celebration in the locker room when we reached .500 for the first time. Tom said 'We want more than .500, we want a championship.'"

"I'll always treasure our friendship," said Mike Piazza, who is the only other player in baseball history to go into the Hall of Fame as a Met. "Tom was always rooting for me to get into the Hall. Two of my fondest memories are walking out of Shea Stadium together after the last game and then when he threw the ceremonial first pitch to me at Citi Field the next year. He was one of a kind."

"Tom and I had a great relationship," said David Wright, who holds many of the Mets' hitting records. "I think he saw a little of himself in me, I was homegrown, just like he was. He called me from time to time, but we would never talk about baseball. We would talk about life."

"Saddened to hear of the passing of Tom Seaver," said Jacob deGrom, the only other Mets pitcher to win more than one Cy Young Award. "Unfortunately, I never got the chance to meet him. Seeing the person he was on and off the field, he is definitely someone I look up to."

"The only thing my dad always told me about Tom was nobody prepared for a game like he did," said Gil Hodges Jr., the son of the manager of the 1969 Mets. "He never left anything to chance."