Harry Kalas, the sincere and sentimental Phillies broadcaster whose smoky voice and singular home-run calls were for nearly 40 years as much a franchise fixture as the "P" on its players' red caps, died yesterday at 73.

"We lost our voice today," said Phillies president David Montgomery.

Mr. Kalas was found unconscious in the broadcast booth yesterday before the Phillies' game at Nationals Park in Washington. He was taken to George Washington University hospital, where he was pronounced dead about 1:20 p.m., the Phillies said. The cause of death was not announced.

"Harry Kalas is the Phillies," said John Kruk, the ex-Phils first baseman and now an ESPN broadcaster.

Phillies and Nationals officials discussed whether to play yesterday's game but chose to because, Montgomery said, Mr. Kalas would have wanted them to do so. However, the Phillies' planned visit to the White House today was postponed with no new date set.

The news of Mr. Kalas' death prompted makeshift memorials around Philadelphia and made headlines on newscasts and Web sites across the country. There was a moment of silence before the Phillies-Nationals game, as well as before the Rockies-Cubs contest at Wrigley Field in Chicago, near Mr. Kalas' boyhood home.

"The Kalas family is overwhelmed by the outpouring of love and affection from all of Harry's fans and friends cross America," Mr. Kalas' family said in a statement. "Especially the Phillies fans whom he loved as much as the game of baseball itself."

Mr. Kalas, a self-effacing Midwesterner who arrived here in 1971, when the Phillies moved into Veterans Stadium and was their lead announcer when they transitioned to Citizens Bank Park 33 years later, seemingly was born to be a baseball announcer.

That destiny was clear enough to classmates at Naperville (Ill.) High School that someone placed these prophetic words alongside the 1954 yearbook photo of the blond kid with the impish smirk:

"Harry Kalas . . . Future Sports Announcer."

His fan's passion for the game, his golden voice, enthusiasm and endearing personality combined to make him not just a widely respected announcer but perhaps this hard-bitten city's most beloved sports figure.

"He was so well-prepared, had such a great set of pipes and was a real professional," said veteran Philadelphia broadcaster Bill Campbell, whom Mr. Kalas replaced with the Phillies. "He was just a wonderful broadcaster."

Despite 38 years in Philadelphia, Mr. Kalas never abandoned the tastes he developed in 1950s Naperville.

He favored garish sport coats, white shoes and belts, and cornball poems and songs. His innate optimism was best expressed by the lyrics of "High Hopes," the 1950s novelty song that Mr. Kalas would gladly and lovingly croon in bars, press boxes or buses.

Next time you're found, with your chin on the ground
There's a lot to be learned, so look around:
Just what makes that little old ant
Think he'll move that rubber tree plant.
Anyone knows an ant, can't
Move a rubber tree plant.
But he's got high hopes, he's got high hopes,
He's got high apple pie, in the sky hopes.

Professionally, Mr. Kalas was, along with Vin Scully of the Dodgers and Ernie Harwell of the Tigers, among the most respected and recognizable voices in recent baseball history. That voice, burnished by a half-century's cigarette habit, became even better known when two local institutions, NFL Films and Campbell's Soup, hired him for voice-over work.

He was Notre Dame football's radio voice for several seasons and for the last few decades had broadcast NFL games as well. He was inducted into the broadcasters wing of baseball's Hall of Fame in 2002. He won 18 Pennsylvania Sportscaster of the Year Awards and in 2003 was a charter inductee into the Philadelphia Sports Hall of Fame.

Through his years here, Mr. Kalas became a comforting and engaging presence on the Phillies' radio and television broadcasts. He was clear, concise and always curious. His long partnership with the late Richie Ashburn, who became perhaps his closest friend, was marked by humorous exchanges and good-natured ribbing.

"Harry was as good a colleague as any sportscaster could hope to have," said Andy Musser, his Phils broadcast partner for 26 years. "He was easy to get along with, and I certainly enjoyed my 26 years sharing the booth with Harry."

Mr. Kalas was present for the greatest moments in Phillies history. He was behind the mike when the 2008 Phils captured the World Series, when Mike Schmidt hit his 500th - and every other - home run, when Steve Carlton won his 300th game.

Oddly, Mr. Kalas did not make the call when, in their 97th year, the 1980 Phillies won the franchise's first World Series championship. At the time, Major League Baseball did not permit local broadcasts of those games.

At the same time, away from the game, Mr. Kalas developed deep roots in the Philadelphia community.

He would emcee athletic banquets, provide voice-overs for local firms' commercials, chat with fans before and after games, record greetings on their answering-machines.

And just as he could emote excitedly over a Schmidt or Ryan Howard home run, he could choke up, especially when discussing Ashburn, whom Mr. Kalas lovingly referred to as "His Whiteness," because of Ashburn's white hair.

Mr. Kalas began his long career here as an unwelcome replacement for the popular Campbell. Working with Ashburn and By Saam, he slowly developed a rapport with his partners as well as his audience.

By the time the Phillies became contenders in the mid-1970s, Mr. Kalas was firmly fixed in the public's mind. His unalloyed allegiance to the team and its players, maybe most especially Schmidt, grew through the years.

His electric call of Schmidt's 500th, a game-winner on a Saturday afternoon in Pittsburgh, was one of his most memorable moments.

"Swing and a long drive, there it is, number 500! The career 500th home run for Michael Jack Schmidt!"

"His voice will resonate in my mind the rest of my life," Schmidt said yesterday in a statement released by the Phillies. "I will never be called 'Michael Jack' again without seeing his smile."

Ball players, who called him "Harry the K," "H-K," or just plain "K," loved and respected Mr. Kalas, who traveled with them and frequently serenaded them from his seat at the rear of their charter flights.

They often asked him to repeat his trademark "Outta Here!" home-run calls or the slow, staccato delivery he used on names that fascinated him, like "Mic-Key Mo-Ran-Di-Ni." Eventually, fans, impressionists and other broadcasters began to copy his unique delivery.

Mr. Kalas was the son of a sports-loving Methodist minister in Naperville, the bustling Chicago suburb that when he was growing up was a leafy small town of fewer than 10,000.

A high school classmate, Carol Drendel, recalled a date with him. The two went to a drive-in in Mr. Kalas' father's Packard.

"He just sat there the whole night," she said in 2002, "and pretended he was announcing a baseball game."

Her late husband, Gib Drendel, remembered in that same 2002 interview how Mr. Kalas would entertain his classmates during history class taught by a hearing-impaired teacher.

"Harry used to cup his hands around his mouth and pretend to be announcing a Washington Senators game," Drendel said. "He'd go, 'Here's the 3-2 pitch from Cam-il-o Pas-cual.' "

When he was age 10, a chance encounter with Washington first baseman Mickey Vernon, a Delaware County native, cemented his love for baseball and made him a Senators fan.

Arriving early for a White Sox game at Comiskey Park, Mr. Kalas asked Vernon for an autograph. Vernon not only gave it to him but brought the young boy into the Senators' clubhouse. Later, the two men became good friends.

While he was a preacher's son, Mr. Kalas was no goody two-shoes. He liked to smoke, gamble, and, until a few years ago, drink. After home games, he would set up at a table in the press-box dining room talking baseball and drinking beer with TV crewmen, visiting writers, scouts, stadium workers, anyone who cared to join him.

On the road, until he stopped drinking, Mr. Kalas was a fixture in team-hotel bars, where he could consume cigarettes and alcohol at a prodigious pace and where he invariably would perform "High Hopes" at some point during the night.

Mr. Kalas graduated from the University of Iowa in 1959 with a degree in speech, radio and television. While there, he worked various Hawkeyes games.

Drafted into the Army, he was stationed at Schofield Barracks in Hawaii. Learning that Bill Whaley, a onetime Pacific Coast League pitcher, owned the South Pacific cocktail lounge downtown, Mr. Kalas went there one night for some beer and baseball conversation. It was a life-changing event.

Whaley informed Mr. Kalas that big-league broadcaster Buddy Blattner was due at the bar in a few hours. Blattner told the young private that the Sacramento Solons of the Pacific Coast League would be moving to Honolulu that year.

When they did, Mr. Kalas applied for the broadcaster's job and got it, submitting a tape from a Minnesota-Iowa game. And since the season started in April of 1961 and he wasn't due to be discharged until July, he persuaded the Army to grant him an early discharge.

By 1965, he had graduated to the big leagues and was doing the Houston Astros' games. Six years later, when the Phillies were due to move into their new South Philadelphia stadium, Bill Giles hired him as part of the team's new beginning. In 2003, when the Phils departed the Vet, Mr. Kalas was still their lead broadcaster and emceed the stadium's emotional closing ceremony.

Gov. Rendell said that as mayor of Philadelphia, he went to a lot of civic and community events, and Mr. Kalas attended nearly as many.

"Harry was with us for 162 games times nearly 40 seasons," Rendell said. "He was everybody's friend. Baseball, because it's such a long season, we tend to develop special relationships with the broadcasters. It's a year-long soap opera. And we were blessed to have Harry in our lives."

Mr. Kalas called baseball "the greatest game in the world" and said that throughout his lengthy career he enjoyed every game he worked.

"Harry was definitely one of the greatest baseball announcers of all time," said Bob Boone, the onetime Phils catcher and now the Washington Nationals' assistant general manager. "It's going to take some time for Philadelphia to get used to being without him."

Mr. Kalas is survived by his wife, Eileen, and sons Todd, Brad and Kane.

In lieu of flowers, the family requested that contributions be sent in Mr. Kalas' name to Phillies Charities Inc., Phillies, 1 Citizens Bank Way, Philadelphia 19148. Contributions will be earmarked for different charities at a later date.

Funeral arrangements were not announced yesterday.