Since 1999, it has been California law that each public school principal write and maintain a School Safety Plan. Every site will be different. At my high school, the JROTC commander was closely involved with developing the emergency procedures. Red backpacks with the room number written on it are kept in all rooms (not just classrooms.) The backpack contains an extremely minimal first aid kit (restocked at the end of every year, and as needed at the nurse's office), a spiral bound booklet of emergency numbers and procedures, a cheap flashlight and batteries, class rosters (for classrooms), a laminated sign with the room number, extra paper and writing implements.

There are two onsite and two offsite assembly areas. There are at least two drills per year for different scenarios (fire/disaster/lockdown.) Every classroom has a landline, at least one networked computer and closed circuit television. (Administration, security, custodians and key staff also have radios.) Every student is given a planner at the beginning of the year which contains a map of school, the evacuation routes and where each classroom meets in the assembly area. (Map is also posted in each classroom.) There are also procedures for before/after school and between classes.

Hope this helps!