Friends and family of Marcus Wheeler gathered at Corona del Sol High School Tuesday night to remember the student who committed suicide on campus earlier that day.
18-year-old senior Marcus Wheeler ran cross country and track for the school.
At approximately 8:50 a.m., administrators alerted the school resource officer (SRO) that there was someone with a firearm in an exterior breezeway near the gym, Tempe Police spokeswoman Molly Enright said.
The SRO called for additional officers and the school was placed on lockdown.
The SRO found Wheeler and tried to talk him into putting down the gun.
Police said Wheeler shot himself in the head and died from his injuries despite life-saving efforts by officers and personnel from the Tempe Fire, Medical, Rescue Department.
Lt. Scott Smith said no other students were present when the shooting occurred and no one else was injured.
Police said there was no apparent threat to other students or staff. At this time, police do not know what precipitated the suicide.
The school arranged for bus transportation and family member pickup of students by approximately 10:15 a.m. School will resume as usual on Wednesday.
His fellow students say they did not see this coming, and that he gave no signs this might happen.
"He should be remembered as someone who never gives up on others' happiness," said friend Ariana Zahedi. "He wants to make sure everyone else was happy, disregarding himself."
"Marcus told me communication is vital, yesterday," she continued. "So maybe that was a sign I didn't catch."
"This kind of thing has a tremendous impact on everyone," said psychiatrist Dr. Mark Welleck, who says people need to talk about their feelings.
"I promised myself today that I'm going to run for him every day on this track," says Zahedi.
Counseling will be provided to students and staff as needed.
A toll-free 24-hour number is available to anyone who may be in crisis or needs someone to talk to, 1-800-203-CARE (2273). Call Teen Lifeline at 602-248-TEEN if you are worried about someone or need help.
Nearly 3,000 students attend the high school, which is located near Rural and Knox roads. Final exams and graduation are next week.
The state baseball quarterfinals and a school band concert that were scheduled for Tuesday have been canceled. Information on possible rescheduling of these events will be announced at a later time.
Wheeler had posted several tweets leading up to Tuesday's suicide.