Killebrew, 74, was considered one of the faces of the Twins franchise, as he played nearly his entire career with the organization, making his debut with the then-Washington Senators on June 23, 1954, as a 17-year-old from Payette, Idaho. He went on to an illustrious career spanning 22 seasons, hitting 573 home runs while making 11 All-Star appearances.
"This is truly a sad day in the history of the Minnesota Twins organization," Twins chief executive officer Jim Pohlad said. "The Twins will remember Harmon for his many on-field contributions, but more importantly for the impeccable quality of his character, his great integrity and his compassion for everyone he encountered."
"Harmon Killebrew personified Hall of Fame excellence in every aspect of his dynamic life," National Baseball Hall of Fame and Museum chairman Jane Forbes Clark said. "Since joining the Hall of Fame family in 1984, Harmon was a beacon of light among his fellow Hall of Famers, always smiling, always enjoying every moment that life delivered at his doorstep. We have so many fond memories of this wonderful baseball hero, and we will miss him enormously."
"Harmon was a Hall of Famer on and off the field," National Baseball Hall of Fame and Museum president Jeff Idelson said. "He was baseball's version of Paul Bunyan, with his prodigious home run power, leading by example in the clubhouse and on the field. Off the field, he emanated class, dignity, and warmth, and he was a great humanitarian. He was so down-to-earth, you would never realize he was a baseball legend. It's ironic that his nickname was 'Killer,' as he was one of the nicest, most generous individuals to ever walk the earth."
"When I learned the news about Harmon today, I felt like I lost a family member," Twins catcher Joe Mauer said in a statement. "He has treated me like one of his own. It's hard to put into words what Harmon has meant to me. He first welcomed me into the Twins family as an 18-year-old kid and has continued to influence my life in many ways. He is someone I will never forget and will always treasure the time we spent together. Harmon will be missed but never forgotten."
Twins players and coaches also spoke before Tuesday's game against the Mariners in Seattle, recalling how humble and kind he was, and about the mentorship he provided.
"It's a tough day," Twins manager Ron Gardenhire said. "Of all the news of late, we knew that he was very sick, and it's just one of those pieces of news that you take, then you reflect, and your thoughts go out to Nita and the family.
"We've lost a really good person and a friend. More than anything, you look at how the man affected people's lives -- his career and his personality. He brought the whole package, and that's not something you see much around the game. The kindness and caring for the people he came into contact with. He left everybody with a very good impression."
Twins first baseman Justin Morneau was particularly saddened by Killebrew's passing, as they lived nearby each other in Arizona, and he loved to pick his brain about being such a prodigious power hitter.
"He was [the] best," Morneau said. "That's the only way to describe him. It's a tough one. Bad things happen to good people. Not that it makes too much difference, but at least he's not suffering anymore. But it still just doesn't seem fair."
Morneau was certainly impressed by the fact Killebrew hit more than 40 homers eight times in his career and was the 1969 American League MVP, but was also equally in awe of his legacy away from the field.
Killebrew was very active in the community, returning to an official capacity within the Twins organization in 1997 as a Special Assistant. In that role he became a regular participant at TwinsFest, the Twins Winter Caravan and other major community-oriented events.
In the community, Harmon and Nita Killebrew also founded the Killebrew Foundation, which helped raise hundreds of thousands of dollars for many charitable organizations across the country. Among those local organizations benefiting from the Killebrew Foundation was the Minnesota Twins Community Fund and Miracle Leagues of Minnesota.
"He was selfless and heavily involved in his charity work once he was done playing, with his foundation," said Morneau, the 2006 AL MVP. "So it was the kind of life we all hope we could end up leading. But I'm not sure anyone in here could measure [up] to the things he accomplished as both a person and a baseball player. So he gives you something to strive for, but it's tough."
Mauer had similar things to say about Killebrew's personality and work in the community, as he met him as an 18-year-old at TwinsFest
"The one thing I'd admired about him since the day I met him is how he treats everybody the same," said Mauer on Friday. "You wouldn't know he's a Hall of Famer when he walks into the room."
Mauer added that one of the most indelible marks that Killebrew left on him was simply working on his autograph, as Killebrew always had a fan-first attitude and made sure his name was legible when signing for fans.
"He would always get on me about my autograph," Mauer said with a smile.
Michael Cuddyer had a similar story, as Killebrew took him aside one time and told him to work on his signature.
"I did a signing with him on Caravan one year, and my signature looked pretty bad." Cuddyer said. "He told me, 'If I see this come through the line one more time I'm walking away and leaving, and the only person these people are going to be mad at is you, because you're the reason I'm going to leave.' From then on I've tried to make it as legible as I can. Every time I sign an autograph, he's in my head, thinking about how it looks."
Killebrew was also a fixture at Spring Training since the 2006 season, when he first joined Gardenhire and wore his No. 3 jersey out on the field. Gardenhire recalled that moment fondly, calling it his favorite memory with Killebrew.
"I thought that was really cool that day to see him in my office shaking my hand and telling me he was so excited to be on the field," Gardenhire said. "That was as great of a moment as you can have as a manager, knowing you rubbed elbows with Harmon Killebrew."
While at Spring Training, Killebrew spent time giving pointers to players, but more importantly, he took time to just chat with players to make them feel better and welcome.
"He never talked mechanics," center fielder Denard Span said. "He'd only say positive things like you're doing good, keep working, keep battling and just keep believing. It was always words of encouragement when he was around."
Killebrew also kept tabs on the young players in the organization, and he surprised many of the players by knowing plenty about them even though they had yet to play with the Twins. That's why the news was tough on Scott Baker, who met him in 2004 while pitching in Double-A.
"It's obviously a very sad day, not only for Twins fans, but a lot of baseball fans," Baker said. "Everybody talks about how great of a player he was, but more importantly we got to see how awesome of a guy he was. He was a great ambassador for the game and a great family man."
Killebrew even made it to Spring Training this year, even after being diagnosed with esophageal cancer in December. It was special for the players to see Killebrew, especially because they were aware of what he was going through.
"It meant a lot, because we knew what he was battling and what was going on with him," Span said. "For me, I didn't ask him how he was doing, but I wanted to so bad. I didn't want him to think about what was going on. I just wanted him to get his mind off [of] what was going on. So for him to be around us, it lifted him up."
But Killebrew's health took a turn for the worse, and many of the players were noticeably saddened by the news.
"It's tough news for everybody," said outfielder Jason Kubel. "He was a great guy, and he was always happy to see us, and we were always thrilled to see him."
The Twins decided to honor Killebrew by hanging up a No. 3 jersey in the dugout and will wear their throwback jerseys at Target Field all year.
"We figured it would be [a] good tribute to pay to him for the rest of the season," Cuddyer said. "I've asked everybody, and I think everybody has complied that we'll wear these uniforms all season when we're at home."
They're also going to wear a specially designed patch bearing Killebrew's No. 3 and will fly a No. 3 flag immediately adjacent to the Twins Territory flag near Target Plaza at Target Field.
"It's fitting," Cuddyer said. "If we could all wear the No. 3 that would be fitting too, but obviously that can't happen. But wearing the patch to remember him is really the least we could do."