A letter sent from Principal Elaine Hofmann to families said Kevin Todd had a 'medical event' at the school and died at a hospital.
Todd had been part of the Apex community for more than 30 years.
"This is a tragic loss for our Apex community and our hearts go out to his friends and family," Hofmann said in the letter.
She asked parents to monitor and be aware of the social media usage of their children, as students may be feeling "anxious, sad, fearful, angry, or vulnerable" about Todd's loss.
"Through encouraging discussion, being supportive of feelings, providing factual information and suggesting positive outlets, you can help your child be aware of and process his or her emotions. Every child is different, and the emotional response may vary in duration," she said.
Because of Todd's sudden death, the school has postponed its Class of 2020/21 Senior Procession that was originally scheduled for Thursday.
"We understand that seniors were looking forward to this event, but we hope that you will appreciate why we are postponing so that we can care for our staff and students during this difficult time," Hofmann said.
Schools counselors at Apex high school are being made available for support.
WCPSS has also partnered with Transitions GriefCare to help support grieving families, students and staff members.