The student was on campus at Florida's Marjory Stoneman Douglas High School when 17 people were killed by gunman Nikolas Cruz a year ago.
The student's name has not been released but Coral Springs police spokesman Tyler Reik said it was a sophomore boy.
Last weekend Sydney Aiello, 19, who survived the Parkland massacre and graduated past year, killed herself reportedly out of grief and "survivor's guilt".
Her mother, Cara, told CNN that Aiello, a student at Florida Atlantic University, suffered from survivor's guilt and had recently been diagnosed with post-traumatic stress disorder. The county medical examiner's office and detectives in the department are reportedly investigating the tragedy.
Ms Aiello said her daughter had never asked for help before killing herself, and spoke to the network to remind people of the resources available to people struggling with mental health issues.
NZ investors act on terror attack
When a video is reported while it's broadcasting, it's "prioritized for accelerated review", Facebook explained. Facebook spokesperson Simon Dilner said it could have done better and it was prepared for regulatory action.
One of those victims was her close friend, Meadow Pollack. "She lit up every room she entered", a GoFundMe page for the Aiello family states.
"It's awful what happened".
Pollack's brother, Hunter Pollack, confirmed Sydney's death on Twitter Friday, noting that "It was devastating to bury another lovely young person in Parkland today". Meadow and Sydney were friends for a long, long time, ' he said. Sydney aspired to work in the medical field helping others in need.
If you or a loved one is feeling distressed, call the National Suicide Prevention Lifeline.