Update: Evansville School Corporation officials and law enforcement met to debrief Friday after a former Reitz student brought a gun on school grounds Thursday. Police Chief Brad Hill praised their efforts, saying everyone reacted just as they practiced during drills. It all started when a witness spotted a young man on Reitz campus with a shotgun. The schools liason called for back up and in minutes, the school was surrounded by law enforcement. The young man fled and was arrested on Old Henderson road. School officials say they will now be looking for at-risk students and warning signs. Thursday: Some Reitz students say they didnt know what was going on initially. Students say what they thought was a drill became very serious when they saw police. They say they learned that a person with a gun was on campus through text messages. And when they began talking they realized it was someone they knew. It is safe to say that there were tense moments inside Reitz High School as the message from the intercom came down. "They just told us the school was on immediate lock down and that we needed to lock the doors and get away from the windows." "Some people were really worried other students were relaxed." Some students also thought it was a drill, that is until they saw police rush in. "A whole bunch of cops started pulling up and were like this is serious." Word quickly spread that there was a person with a gun on campus. And through text messages it suddenly became apparent who the suspect was. A former student, a junior, who student Nick Fulling says transferred to an alternative school just a few weeks ago. "He had made some suicidal comments." But fulling says it was still a shock. "He seems like a nice guy. I mean he seemed just like an average person really." The whole experience left some students shaken up. Many calling parents to pick them up. Even against the recommendation of the EVSC. "My last period of class there was about five people in there. It was crazy." And coming back to school tomorrow for some, wont be any easier. "Im kinda in shock cause you never really think it would happen to you or your school."