Friday night, February 12, 2016, ABC 20-20 aired a special “Silence Broken: A Mother’s Reckoning”, as Diane Sawyer interviewed Sue Klebold, the mother of Dylan Klebold. A major preview had been aired on World News Tonight. The details of the April 19, 1999 incident in Littleton, CO are here .
Sue Klebold would later survive an episode of breast cancer. She describes it as beautiful winter scenery in Colorado passes.
School shootings had not been on the national radar screen until the late 1990s, and then has exploded. Most of the incidents involve people getting guns formerly purchased legally, in homes of parents or relatives.
The interview leaves the impression that there is very little mothers can do ahead of time to know when something is wrong.
Wikipedia attribution link for Invesco Field picture in Devner .