Oct. 20 is World Osteoporosis Day, a day to show support for those who have osteoporosis — the thinning of bone tissue and the loss of bone density over time — and to raise awareness on what can be done to prevent it.  The decrease in bone density makes a person more vulnerable to fractures and broken bones.  To maintain strong bones and lower the risk of osteoporosis, exercise regularly, and eat a balanced diet with sufficient amounts of vitamin D, calcium and protein.  Test your knowledge of osteoporosis with WebMD’s Osteoporosis Quiz.

Wear purple on Oct. 20, Spirit Day, to show your support for lesbian, gay, bisexual and transgender youth, and take a stand against bullying.  Spirit Day was started by teenager Brittany McMillan in response to suicides among LGBT youth.  Celebrities pledging to go purple for Spirit Day include Conan O’Brien, Aziz Ansari, Julianne Moore, Carson Kressley, Chaz Bono, Padma Lakshmi and many more listed here.

Also on This Day:

1968 Jacqueline Kennedy Marries Aristotle Onassis

Five years after the assassination of President John F. Kennedy, Jacqueline Kennedy married Greek shipping magnate Aristotle Onassis.  The wedding took place on a private island in Greece.

1973 Watergate Scandal’s ‘Saturday Night Massacre’

Attorney General Elliot Richardson and Deputy Attorney General William Ruckelshaus resigned after refusing President Nixon’s orders to fire Watergate Special Prosecutor Archibald Cox.  Solicitor General Robert Bork carried out the order and dismissed Cox.  Following his dismissal,  Cox gave his opinion on the Watergate tapes.

1977 Lynyrd Skynyrd Plane Crash

A plane carrying members of the rock band Lynrd Skynyrd crashed in Mississippi.  The plane was on route from South Caroline to Louisiana.  Six people were killed in the crash, including three of the band’s members -singer Ronnie Van Zant, guitarist Steve Gaines and backup singer Cassie Gaines.

2010 Clarence Thomas’ Wife Calls Anita Hill

Nineteen years after Clarence Thomas’ Supreme Court justice confirmation hearings, Thomas’ wife, Ginny, called Anita Hill seeking an apology for Hill’s testimony against Thomas.  In October 1991, Anita Hill testified before the Senate Judiciary Committee, accusing Clarence Thomas of sexual harassment.  Anita Hill stood by her testimony, and did not apologize.

Famous Birthdays

1882 Bela Lugosi

1931 Mickey Mantle

1950 Tom Petty

1956 Danny Boyle

1958 Viggo Mortensen

1971 Snoop Dogg

1979 John Krasinski

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