Providing alternative escape routes:

The first thing to check is if everyone can turn away from the fire and move safely away from it.

For this to be the case there will have to be at least two exits that everyone can get to. Then, if one exit is inaccessible due to the location of the fire, everyone can go to another exit.

The second part of the aim is that people, having turned away from the fire and started to move towards another exit, can move safely away from it.  This is stated because it will not be satisfactory if the alternative exit is not large enough to allow everyone to flow through it quickly enough causing a queue to form that endangers the people at the back of the queue.