One of the first tweets from OSU after Monday’s attack on campus was warning students to "run, hide, fight."

It’s actually a Homeland Security “check list” directive.

Tactical Defense Instructor Matt Schafer doesn’t mince words when he teaches it to students.

"Treat it like your life depends on it because it does.” Says Schafer.

CSU Sophomore Marcus Malave admitted, as he watched the chaos unfold 2 hours down the road, "Happening to them made it seem more realistic that it could happen to us at any moment."

It’s exactly why Schafer has a job.

On Monday, he broke down 'Run. Hide. Fight.' for a focus group of CSU students.

#1 We're going to try to run away. Call 911. Be a good witness. Run to cover to a safe can protect you.

#2 if you can't run away, hide. We're going to “shelter in place”. Get out of the shooter’s view in some place they can't see us. Physically make it difficult for him to get to us. We are going to barricade the doors. We’ll put objects in the way. We’ll get as much distance and cover between them and us as possible.

Lastly #3, we're going to fight if we are unable to run away. If we are hiding and they find us, we're going to fight in a confined space. We’re going to try to fight with him in a doorway barricaded up but they are struggling to get through. Don’t let him through the doorway. We'll use weapons of opportunity like mace, pepper spray, nail files, pens. You are fighting for your life," said Schafer.

The CSU students who went through the drill admitted they would feel less of a sitting duck, if ever in the same position as the one that unfolded at OSU.

"Yeah it was empowering. Now I know exactly what to do," said Freshman Tiffany Roberts.

“There's no need to panic as long as you have down what you need to do. Rather than being a victim we learn to be survivors so we’re not just another casualty on the news,” said CSU Freshman Lauren Hodges.