On this day, July 18 …

1969: U.S. Sen. Edward M. Kennedy, D-Mass., leaves a party on Chappaquiddick Island near Martha's Vineyard with Mary Jo Kopechne; sometime later, Kennedy's car goes off a bridge into the water. Kennedy is able to escape, but Kopechne drowns. The scandal would dog Kennedy the rest of his life.

Also on this day …

A.D. 64: The Great Fire of Rome begins, consuming most of the city for about a week.

The Great Fire of Rome begins, consuming most of the city for about a week. 1940 : The Democratic National Convention at Chicago Stadium nominates President Franklin D. Roosevelt (who is monitoring the proceedings at the White House) for an unprecedented third term in office; earlier in the day, Eleanor Roosevelt speaks to the convention, becoming the first presidential spouse to address such a gathering.

: The Democratic National Convention at Chicago Stadium nominates President Franklin D. Roosevelt (who is monitoring the proceedings at the White House) for an unprecedented third term in office; earlier in the day, Eleanor Roosevelt speaks to the convention, becoming the first presidential spouse to address such a gathering. 1947: President Harry S. Truman signs a Presidential Succession Act, which places the speaker of the House and the Senate president pro tempore next in the line of succession after the vice president.

President Harry S. Truman signs a Presidential Succession Act, which places the speaker of the House and the Senate president pro tempore next in the line of succession after the vice president. 1985: The world gets its first look at the wreckage of the RMS Titanic resting on the ocean floor as videotape of the British luxury liner, which sank in 1912, is released by the Woods Hole Oceanographic Institution.

1989: Rebecca Schaeffer, 21, from the cast of TV sitcom “My Sister Sam,” is shot to death at her Los Angeles home by obsessed fan Robert Bardo, who would be sentenced to life in prison.

2009: The Taliban posts a video of an American soldier who’d gone missing June 30, 2009 from his base in eastern Afghanistan and was later confirmed to have been captured. (In the recording, the soldier, later identified as Pfc. Bowe Bergdahl, says he was "scared I won’t be able to go home."