Leader signals an emergency, everyone evacuates in a safe manner and meets at the designated meeting point. Register is taken to ensure all present.
Register, stopwatch / timer, emergency signal (eg whistle)
A leader will signal an emergency using agreed signal
One leader leads the way to Meeting Point
Final (pre-agreed) leader checks register collected and no one inside, then leaves the building closing the door behind them
Beavers line up in lodges at meeting point and the register is checked
The whole process could be timed to see how quick everyone evacuates
Repeat the exercise as required