Dire presidential messages throughout history

Donald Trump on Tuesday said the coronavirus death toll in America could quickly reach almost a quarter of a million people, and warned Americans to prepare for a “very, very painful two weeks.”
Trump said there could be between 100,000 and 240,000 deaths even if Americans followed the strict social distancing guidelines that the White House has recommended remain in place until the end of April, adding that the situation had become “life and death.”
Trump, who calls himself a "wartime president" combating an "invisible enemy," isn't the first president to deliver somber news of live and death to the American people.  Almost every sitting president has had to bear that burden. 
Here are some of the dire messages delivered by presidents during times of crisis, each centered around terrorist attacks, wars and other global disturbances.