Has your school thought the unthinkable yet? David Kibble is a calm and rational deputy head who believes passionately that colleagues should explore their worst nightmares.
What if that light aircraft innocently circling the sports field came down on the science block? What if the field trip got into difficulties in a blizzard on Dartmoor? Or at a more mundane level, what if all the school's computer data was lost in a fire or flood?
Mr Kibble began thinking about nightmare scenarios, he says, some years ago when primary schoolchildren were involved in a fatal accident at Land's End. Since then the tragedies which have afflicted schools have only got worse and he has moved on from safety and disaster planning for his own school, Huntington, on the outskirts of York, to a book which distills what he has learned in the process.
Huntington secondary school got into the disaster planning business when a governor read the Gulbenkian Foundation's book, Wise Before the Event. Impressed, the head and senior management team turned to Mr Kibble because they thought this was "his sort of thing".
They were not wrong. As a naval reserve Lieutenant Commander, Mr Kibble had spent much of his spare time during the previous 15 years carrying out disaster planning on a very big scale indeed at HMS Ceres, a naval communications and training centre in Leeds.
"The armed forces spend much of their time engaged in this sort of activity," he says. "My remit was to work on planning for the merchant navy and the major ports. What would happen if there was a terrorist bomb, a major fire, or infiltration by enemy forces."
Every port, he says, has its disaster plan, as do many civilian organisations. On the bridge of a ship there are always written instructions on what officers should do in an emergency.
"What people don't realise is the effect of the panic response. It was brought home to me very forcibly when my own child was scalded and my wife and I had to deal with the crisis. At first I kept calm and got them both to the car to drive them to hospital. But when I set off I found I simply couldn't remember the way. My wife had to take over and guide me over very familiar territory."
It is not until you have been through that sort of trauma, Mr Kibble says, that you realise that you will not necessarily keep calm and do the right thing in a crisis. Even worse, you may actually do the wrong thing and compound the disaster because you can't think straight.
When you are responsible for children and young people, that is not a risk heads and teachers can afford to take. The only way to overcome the disorienting effects of panic, he says, is to plan for safety and be prepared for the unexpected. And the larger the organisation, the more complex that process is and the more it needs co-ordination and even rehearsal.
What he discovered, he says, when he began to look at his own school's procedures for everyday safety and emergencies, is how complex this sort of planning has become in the modern world.
An evacuation to deal with a small fire revealed that it was not even clear who was in charge in an emergency and that it was impossible for the head - at the front of the school to meet the fire brigade - to communicate with the deputy on the field with the evacuated pupils.
Challenging a stranger in the corridor, who turned out to be a student teacher, revealed how in a large secondary school no one individual can distinguish between those who have a right to be on the premises and those who do not. At Huntington, the caretakers are now in radio contact, the staff have the use of two mobile phones and bleepers are available for the IT technician, the first aider and lunch-time supervisors.
"The military use the term Three Cs - command, control and communication. They are just as relevant for schools," Mr Kibble says. The whole process of planning for the worst case throws up questions which it might be vital to have answers to in a real emergency. For instance, the fire alarm will get everyone out of the school, but what if an armed intruder was stalking the corridors and you wanted to let staff know there was a problem but that it was safest to keep children in their classrooms. The answer? Five rings on the end-of-class bell to alert all teachers and summon those who are free to a central point. Five more rings as an all-clear signal when the emergency is over.
When Huntington showed its emergency plan to social services and the police locally they made just two suggestions. Social services reminded the school that teachers as well as children might need counselling after a tragedy. The police suggested that everyone in school should wear an identity badge and anyone without one should be immediately and politely challenged.
Mr Kibble now sports his ID badge with the rest, and visitors are booked in and out very carefully. What people don't realise, he says, is that this sort of planning is not only done by the military these days. And it is not just people who are at risk. Since the devastating damage done by IRA bombs in London and Manchester, industry and commerce also have their contingency plans for personnel, property and, crucially, their computer systems.
How many schools, he asks, make sure that all their computer data is backed up and stored safely overnight as many commercial concerns do as a matter of course? After a fire or a flood, a school can be up and running in temporary accommodation very quickly if everything on disk, from the administrative files to class work-sheets, is safe.
Mr Kibble's training manual draws heavily on Huntington's experience of implementing his very detailed procedures for dealing with contingencies from pupils involved in accidents, damage to school buildings, intruders in playgrounds, abusive parents, assault by pupils and problems on out-of-school trips. He does not duck the emotive issue of dealing with the deaths of pupils or staff.
Much of his planning involves exhaustive check-lists which attempt to pre-empt problems. The objectives are to clarify who is responsible for what, who is in control and what procedures have to be followed by particular individuals in an emergency. In a fire, he says, it is just as important to be sure that the caretaker will switch off the gas supply as it is to know that the head is responsible for calling the fire brigade.
Such a mass of paperwork might be expected to meet some staff resistance, but in practice it is not like that, he says. Pre-planning should help everyone to function effectively if the unexpected happens and make sure that nothing, from liaising with parents and the Press to keeping in touch with the PE staff out on the field, is forgotten in the heat of the moment.
Communication is vital and money spent on mobile phones well spent. In his experience, Mr Kibble says, if you have got written procedures, for instance to cover all eventualities on a school trip, staff actually feel safer and hopefully if something happens which has not been anticipated, they will have the transferable skills to cope with that too.
Safety and Disaster Management in Schools and Colleges, by David G Kibble, is published by David Fulton Publishers, paperback pound;19.99.