The focus of the exercise was what happens after the emergency ends, how students can be safely reunited with their guardians and making sure everyone is on the same page.
For students like San Marcos High senior Kevin Morales, the exercise was a stark reminder of how dangerous reality can be.
"It felt kind of real you know they were asking questions like they would as if it were a real shooting," said Morales.
The exercise played out how students would be reunited with parents in an emergency.
"It’s a way to add order to a process that I don’t want to invent on the spot," said John-Michael Keyes, Executive Director of "I Love U Guys" Foundation. "How many of you asked the student ‘do you know who this person is’ when they had a visual, when they were making visual contact with that person."
Students, school staff and first responders from throughout Hays County came out for the exercise.
"It was just cool getting to know what they go through in everyday life, rather than just like judging them and hating on them. You know, because they’re gonna save your life at the end of the day," Morales said.
The training used protocol developed by the "I Love U Guys" Foundation.
"The foundation was founded in 2006, when a stranger entered my daughters high school in Plaque Canyon Colorado and held seven girls hostage. While my daughter was held hostage she sent a text message ‘I love u guys’ and ultimately the stranger killed Emily, and the SWAT team killed him," Keyes said.
School shootings have continued to rise after Emily's death. There were 93 incidents with deaths last school year compared to 23 in 2000-01, according to the National Center for Education Statistics.
"Really think that we can advance the needle that we can change our cultures," Keyes said.
Doug Wozniak, director for safety at San Marcos ISD, said changes have been made following the mass shooting at Robb Elementary in Uvalde.
"As far as how we look at drills and just having obviously a much better understanding of your exterior doors and making sure those are locked," Wozniak said.
All the training materials from the workshop and exercise are available for download on the "I Love U Guys" Foundation website.