On Aug. 1, 1966, The University of Texas and the city of Austin experienced its darkest day.

On that hot summer day, a 25-year-old student and former Marine by the name of Charles Whitman went to the top of the UT Tower and began shooting. Forty-five people were shot, and 13 of them died that day. At the time, it was the worst mass murder in a public setting in U.S. history.

News 8 Austin's Paul Brown explores The University of Texas Tower shooting 40 years later in a five-part series and an hour-long special.

Part 1: What happened
Forty years ago, the University of Texas became the scene of one of the first mass murders in recent U.S. history when an ex-Marine sharpshooter opened fire from the top of the Main Building Tower.

Part 2: Who was Whitman?
The 25-year-old ex-Marine rifleman didn’t excel at much in life other than being an expert marksman. Charles Whitman gained notoriety when he shot at least 45 people from The University of Texas Tower, before police took him down.

Part 3: The men who ended the killing
Austin police officers Houston McCoy and Ramiro Martinez were forever connected by the events of Aug. 1, 1966. Their lives took different after their heroic moment that ended a sniper's madness.

Part 4: Societal impact
Charles Whitman’s sniper shooting atop the University of Texas Tower changed society’s sense of innocence in Austin and beyond.

Part 5: Symbolism of the Tower
The 307-foot-tall Tower at The University of Texas didn't close to visitors after Charles Whitman's shooting spree, but it did become a constant reminder of the events of Aug. 1, 1966

Part 6: Interview with Cheryl Botts Dickerson
In 1966, 19-year-old Cheryl Botts Dickerson was the last person to speak with Charles Whitman when she and another young man encountered him in the University of Texas Tower.