“Mr. Cub” Ernie Banks, 20th century power-hitting shortstop for the Chicago Cubs, died Friday at Northwestern Memorial Hospital. He was 83.

Major League Baseball and the Chicago Cubs announced his death on Friday, and they did not give a cause. Longtime teammate and fellow Hall-of-Famer Billy Williams said that Banks had fallen just over a week ago but he had no further information.

The news of his death spread quickly throughout the sports world Friday, and many took to Twitter to express their condolences. Anthony Rizzo, who is currently a first baseman for the Cubs, tweeted that what Banks has done for baseball and for everyone he has ever touched “will never be forgotten.” And “The Big Hurt” Frank Thomas, former White Sox designated hitter and first baseman, tweeted that Banks always put a smile on his face. He called him a “special man.”

Chicago Mayor Rahm Emmanuel was close behind when he released a statement. He stressed that Banks was “more than a baseball player” and that he loved Chicago as much as he loved baseball. He added that Banks will be “watching over his team” this year.

President Obama and his wife, Michelle, also grieved over the loss of Ernie Banks. They expressed their condolences to the family and any other Chicagoans or “baseball fans who loved him” in a joint statement on Saturday. President Obama said that Michelle used to watch him play with her mother as a child. And he called Mr. Cub an “incredible ambassador” for both baseball and the city of Chicago, according to the New York Times.

The Cubs paid tribute to Banks on the Wrigley marquee Friday night. And Cubs left flowers and beer cans, which were said to be a toast to the legacy of Mr. Cub, near the gates of Wrigley Saturday morning. Those hoping to tribute Banks at his statue outside of Wrigley Field will have to wait until opening day. It is currently being restored.

Banks was the first African-American to play for the Cubs and his jersey was the first that Cubs retired. No. 14 hangs from the left-field foul pole at Wrigley. He hit 512 home runs and won back-to-back National League MVP titles in losing seasons. He played 2, 528 games in his 19-year career with the Cubs, including 14 All-Star Games, but none of them were in the playoffs. The team had only one winning season in the first 14 years Banks was on the team.

Mr. Cub was accomplished, but he also displayed an unforgettable optimism that epitomizes the Chicago Cubs fan’s outlook that “there is always next year,” despite their losing streaks. And he could always be counted on to say “It’s a great day for baseball. Let’s play two!”

This could be part of the reason he is known by generations extending far beyond his playing career that ended in 1971. He was the most popular Cub in a franchise dating back to the 1870s and became such an institution in Chicago that he could be grouped with Michael Jordan, Studs Terkel, George Halas and first Mayor Daley.

Chairman of the Cubs, Tom Ricketts, said that Banks was of great importance to the Chicago Cubs, to Major League Baseball and to the city of Chicago. He called Banks “ever optimistic and kind hearted.” And he said that Ernie Banks “is and always will be Mr. Cub.”