USA TODAY - The traumatic assassination of John F. Kennedy on Nov. 22, 1963, marked the debut of live, round-the-clock TV coverage of big news. Here's how it might have played out on social.
11:37 a.m.: The president and first lady Jacqueline Kennedy arrive at Love Field in Dallas. They embark on a motorcade through the city accompanied by Vice President Lyndon B. Johnson and his wife, Lady Bird, as well as Texas Gov. John Connally and his wife, Nellie.
• Pics and video of the Kennedys flood Instagram. Vines are tweeted and retweeted, as are pics of Jackie with red roses.
• Selfies taken along the parade route are shared on Facebook, Instagram, Twitter, Snapchat.
12:30 p.m.: Three shots are fired at the Kennedy motorcade at Dealey Plaza.
• Tweets instantly begin appearing about the shots and about the chaos at the scene.
• Photos of Secret Service agents rushing to the president's limousine appear on Facebook.
• Speculation about just what has happened floods Twitter and Facebook, as does concern about the fate of the president. (Was he shot?)
• "I'm here. I'm OK" tweets start appearing.
12:35 p.m.: The networks announce that the president has been shot. The presidential limousine arrives at Parkland Hospital.
• The first and most iconic tweets and Instagrams receive a string of replies from news organizations, asking for more information and permission to repost.
• People along the route tweet and Instagram pics of the motorcade speeding to the hospital and share photos on Facebook.
• "What's going on?" tweets proliferate.
12:40 p.m.: Abraham Zapruder uploads his raw footage of the assassination to YouTube. So do many others.
• Hashtags such as #Dallas and #Presidentshot start trending and abound on Twitter, Facebook, Instagram and G+.
• Twitter is overwhelmed with reports that Johnson has been hit, that Connally was shot. Apprehension about the fate of the First Lady mounts, and the hashtag #whathappenedtojackie blows up.
• People begin retweeting tweets from the Dallas Police feed: "Investigation underway. No information at this time."
• Someone starts a Storify.
12:45 p.m.: Dallas Police tweet a description of the suspect. Retweets immediately follow. The description is widely shared on Facebook.
• Parkland Hospital tweets: "The patient is being treated. We have no other additional information at this time." Speculation that the president has died appears on Twitter and other social media venues.
• Detailed discussions of bullet wounds to the head appear on a Reddit thread. Someone starts a Reddit ELI5 discussion (Explain Like I'm 5): What happens if the president is in coma for a long time?
12:50 p.m.: Twitter tweets of a system failure because it is overloaded.
12:55 p.m.: A local radio station tweets the president is dead. The tweet is instantly and widely retweeted.
• Many news organizations hedge their bets: "REPORT: President Kennedy is dead."; "Unconfirmed reports say President Kennedy is dead."
1 p.m.: President Kennedy is declared dead.
1:05 p.m.: The White House press secretary and JFK's Twitter account issue an official statement that the president has died.
• Reddit launches a search for the killer, complete with photos of people at Dealey Plaza.
1:15 p.m.: Mainstream media outlets erroneously report the number of shooters and their identities. The mistakes are quickly knocked down by authorities.
1:22 p.m.: Jim Romenesko posts about the erroneous journalism on his media blog.
• A rifle is found on the sixth floor of the Texas School Book Depository overlooking Dealey Plaza.
1:45 p.m.: BuzzFeed publishes a list of 12 things you didn't know about the Texas School Book Depository.
• Twitter accounts of Dallas Morning News reporters and other local journalists spike.
2 p.m.: Lee Harvey Oswald is arrested at the Texas Theater for the murder of Dallas police officer J.D. Tippit. Oswald is already a suspect in the president's death.
2:30 p.m.: Lyndon Johnson is sworn in as president.
2:40 p.m.: Politico posts an analysis of what the Johnson presidency will look like.
3 p.m.: Social media sites are packed with tributes to the slain president.
• BuzzFeed publishes a list of 12 things you didn't know about Lee Harvey Oswald.
• People save Oswald's Facebook page, anticipating that the social networking giant will soon shut it down. Other Lee Harvey Oswalds receive threatening messages on their Facebook pages.
3:45 p.m.: Kennedy haters post ugly messages about the dead president, triggering massive explosions of outrage. Publicshaming.tumblr.com posts examples of the tasteless tweets.
11:26 p.m.: Lee Harvey Oswald is charged with the murder of President Kennedy.
11:31 p.m.: Jack Ruby checks in on foursquare at the Carousel Club.
Contributing: Jacqui Barrineau, Patty Michalski, Emily Brown, Desair Brown and Roger Yu