Today in television history: Cronkite breaks news of LBJ's death

(CBS News) Tuesday marks the 40th anniversary of former President Lyndon B. Johnson's death. The day also made television history when Walter Cronkite announced the news while talking to the former president's press secretary on the phone live on air.

On January 22, 1973, Cronkite held the phone receiver to his ear on the CBS "Evening News" and said he is talking to LBJ's top spokesman.

"Can you hold the line just a second?" Cronkite says into the receiver, before explaining that the former president died in an ambulance plane on his way to San Antonio, Texas.

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