Captioning sponsored by cbs this is the cbs evening news with scott pelley. Good evening. This is our western edition. This was supposed to be one to have the happiest nights of marian sanchezs young life. Like so many other teenagers, this time of year, she was looking forward to going to her prom tonight. With that oldest of High School Traditions childed head on with a new and alltoofamiliar School Reality violence. Maren was stabbed to death today, allegedly by a classmate, in a high school in milford, connecticut. Vinita nair is there. Reporter the attack happened just after 7 00 a. M. As students were headed to first period class. The victim was in the hallway near a stairwell at Jonathan Law High School in milford, connecticut, when she was allegedly attacked with a kitchen knife. Milford police chief keith mello a member of the school staff witnessed a portion of the assault, and she along with other members of the school staff, discovered the victim to have lifethreatening inj