AUSTIN (KXAN) — It has been 50 years since a man went up the University of Texas at Austin Tower and started shooting. The bell tolled and the UT Tower clock stopped at 11:48 Monday morning to mark the time the shooting started.

A new memorial now stands in the Tower Garden to honor the 17 people killed and the 30 others wounded in the 1966 attack.

University officials acknowledged and apologized for taking decades to finally commemorate the UT Tower shooting.

The first plaque to commemorate the event wasn’t placed until 1999 and many say it wasn’t fully achieved until Monday. A group of PhD history students wanted to give a complete history of the shooting and why it took so long for the public to take note.

After the mass shooting, many feared the iconic tower, the centerpiece on campus, would be remembered for the gruesome details of Aug. 1, 1966. Public amnesia set in.

“This was a type of event that people just didn’t know how to discuss. There weren’t grief counselors the way we have them on campus now,” said Rebecca Johnston, a graduate history student at UT Austin. Johnston is one of the 11 students involved in the effort called BehindtheTower.org, a public history project using archives, witness interviews and historical documents to present the shooting like never before.

History professor Joan Neuberger, who oversaw the project, says only one historical book was written on the topic until this year.

“You can argue it was the most important event in the history of Austin in some ways and yet there was so little about it,” said Neuberger.

They separated the tasks to make the study come to life. One section looked into the medical history of Charles Whitman, one looked into the archives and one looked into the tower.

“It’s important for me to go up there and understand what really happened and see the sights,” said John Lisle, who focused on the Tower itself.

Itza Carbajal dug into how people remember and why a large physical reminder is so important to commemorating the victims, survivors and moving on.

“The first plaque just talked about the event and the new plaque acknowledges the people that were affected by the event,” said Carbajal.