Depression linked violence has unfortunately been linked to mass deaths and suicides for a long time.
Research has shown that people who have depression are three times more likely to commit a violent crime.
On April 20th, 1999, Dylan Klebold and Eric Harris, both reportedly suffering from depression, opened fire in their high school.
Klebold and Harris injured 21 people, but killed 15, including themselves. The deaths were mixed with students and faculty.
Each death reportedly had no meaning to the killers. Prior to the massacre, Klebold and Harris recorded home videotapes apologizing to their parents. They continued by mentioning they wanted to kill as many people as possible, and they even created homemade bombs to help do the job.
Thankfully the bombs did not detonate, because the death toll could have been much higher. The Columbine High School shooting is one of the deadliest massacres and has resulted in depression for the victims who survived, a continuing cycle of violence and sadness.