Please, for us in the UK - what is a lockdown, and how would it apply to a school? We have a lot of passive security to make sure that people can't get in, and a bombscare evacuation procedure, and a system for alerting senior staff to difficulties.

The nearest we came to the tornado story was a strong gale in 1990, when parents came and took their children home early, through streets with falling chimneys. We couldn't hold children in the circumstances, though our building had already shown it was capable of standing up to winds of the force being experienced.

Penny