Tomorrow marks 25 years since that dark day of April 20, 1999, when a teacher and twelve students at Columbine High School in Littleton were killed by two fellow students. There will be a vigil to honor those impacted by the Columbine shooting at 7:30 p.m. today, April 19, at which speakers will honor the victims and families; the location is TBD, depending on the weather…