Every school district needs one. Some are online, others are at the school for view.
What is an Action Plan? Some states have legislation. California Law
Basically each school ( and district) should have a plan in place for most emergencies and how they will follow procedures in the event that something happens during the day while children are at school.
Ask to see a copy of your schools action plan. If they do not have one, well suggest right quick that you would like to be on a committee to get one started!
CSPAN and NSBA talking about school plans:
http://www.c-spanvideo.org/program/Negron