"We lost our voice," Phillies president David Montgomery said.
Kalas, 73, had been looking at the Phillies' lineup and talking to players inside the visitors' clubhouse at Nationals Park just minutes before he took the elevator to the Phillies' broadcast booth, where he was found unconscious at about 12:20 p.m. Phillies broadcasting manager Rob Brooks performed CPR on Kalas before medical personnel rushed him to George Washington University Medical Center, where he died at 1:20 p.m.
The cause of death was unknown. Funeral arrangements are pending.
The Phillies played their game against the Nationals and won, 9-8, but that hardly mattered. Kalas, a Philadelphia icon, had passed.
"I heard Harry's voice probably for the first time as a 9-year old kid and grew up listening to Harry and Richie Ashburn," said Phillies left-hander Jamie Moyer, who grew up a Phils fan in Souderton, Pa. "That's what I knew as a kid. I came over here in 2006 and it was the same voice. Just a super person to be around."
"What a sweetheart," said Red Sox manager Terry Francona, who was the Phillies' manager from 1997-2000. "A voice that is unmatched. I used to tease him all the time. I'd say, 'Harry, I feel like I hear you more in the winter than I do in the summer,' because he'd be on a commercial or a football game or radio. Everybody wanted him."
Kalas was a Hall of Fame talent with a renowned voice and delivery. He was inducted into the broadcaster's wing of the National Baseball Hall of Fame and Museum in 2002, having won the Ford C. Frick Award, which is presented to broadcasters who made major contributions to baseball.
Kalas, who is survived by his wife Eileen and sons Todd, Brad and Kane, had been a Major League Baseball broadcaster for 44 years, spending the past 39 years with the Phillies.
While Philadelphians knew him as the narrator of their summers, fans across the country might have known him better as the voice for NFL Films or his voice-over work in commercials. But baseball is what Kalas loved the most, and the baseball community expressed their condolences en force Monday.
"Major League Baseball has lost one of the great voices of our generation," Commissioner Bud Selig said. "Harry Kalas was an outstanding ambassador for the game ... Baseball announcers have a special bond with their audience, and Harry represented the best of baseball not only to the fans of the Phillies, but to fans everywhere."
Everybody liked Kalas, and he seemed to like everybody.
Kalas had such status with the Phillies that he sat in the back of the team's charter flights, which typically is reserved for players.
"He came up to me today, I think right before he was about to head up to the booth and asked me if I would have his step-daughter be my guest to go to the White House," Phillies first baseman Ryan Howard said. "I told him, 'Yeah, that's no problem. Absolutely no problem.' He was happy about it."
The Phillies had been scheduled to visit President Barack Obama on Tuesday at the White House, their last celebration for winning the 2008 World Series championship. That visit has been postponed.
"He damn sure will be missed," said Dallas Green, who managed the 1980 World Series champion Phillies.
Kalas had missed the beginning of Spring Training after recovering from an undisclosed medical procedure. He arrived in Clearwater, Fla., in March, entering the final year of a three-year contract. He turned 73 on March 26. Kalas was not scheduled to broadcast on his birthday, so asked why he was at Bright House Field that afternoon he smiled and said, "For the love of the game."
He chuckled and kept walking.
But some worried about Kalas' health. He was noticeably thinner and seemed to have less energy than in the past.
"I was worried ... about him," Green said.
But every time fellow broadcaster Tom McCarthy asked how he was feeling, Kalas always responded, "I'm feeling better every day."
"You never think it's going to happen anyway, but I thought he was getting stronger with each passing day," McCarthy said.
McCarthy and the rest of the broadcasters went on without him Monday, and the players played knowing they would never hear one of Kalas' famous "Outta here!" calls for one of their home runs again.
"I know I can speak for the Phillies when I say Harry Kalas is loved by everyone," Hall of Fame third baseman Mike Schmidt said. "All of us could relate to our daily confrontations with his smile, his charm, and his warmth. He spread his passion for people, and baseball, all over the country for almost 50 years. His voice will resonate in my mind the rest of my life. I will never be called 'Michael Jack' again without seeing his smile."
Kalas was born March 26, 1936, in Chicago. He grew up in Naperville, Ill., and graduated from the University of Iowa in 1959. He spent two years in the Army stationed in Hawaii. A member of the original Astros broadcast team in 1965, Kalas joined the Phillies six years later.
"Harry was a special friend of mine and my family for 44 years," said Phillies chairman Bill Giles, who hired Kalas. "Baseball broadcasters become an integral part of baseball fans' families. They are in the homes of fans every day for the entire season. No one will ever be able to match the joy Harry and Richie Ashburn brought to our fans for all those years. He had a great voice, understood and loved the game, and loved people."
"It's a very sad thing to have happen," said Astros general manager Ed Wade, who started his baseball career as a public relations intern for the Phillies in 1977. "You have our four decades of a guy being the voice of the Phillies. He wasn't on the national stage, but everyone knew that Harry Kalas and Phillies baseball were intertwined."
And because they were so intertwined, Phillies baseball will never sound the same again.
Kalas' family released a statement Monday: "The Kalas family is overwhelmed by the outpouring of love and affection from all of Harry's fans and friends cross America. Especially the Phillies fans whom he loved as much as the game of baseball itself."
In lieu of flowers, the family is requesting contributions be sent in Kalas' memory to Phillies Charities, Inc., Phillies, 1 Citizens Bank Way, Philadelphia, PA 19148.
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.