AUSTIN (KXAN) - It's been one year since UT sophomore Colton Tooley walked onto campus wearing a black suit and mask, firing off rounds from an AK-47.
The 19-year-old then killed himself on the sixth floor of the Perry-Casteñada Library, jolting students and staff from their daily routines and turning the placid morning hours into a chaotic, surreal scene.
UT police sent the first text message and email alert to students and staff 18 minutes after shots were fired, and sent updates throughout the day urging those off campus to "STAY AWAY" and those on campus to "lock doors."
Days after the shooting, students thanked UT police for their quick response and created a sign-up drive for the Campus Emergency Text Alert system, encouraging students who weren't already on the alert list to subscribe to the service.
Since the shooting, UT has had 12,000 new people register for their text alert system, according to the University.
UT's response to the shooting has encouraged other schools to set up similar alert systems.
Texas State University in San Marcos started its own text alert program in response to the UT incident, and since November 2010 have had more than 10,000 people register for their emergency alert system.