When operating at an emergency scene, why should a firefighter scan the outside of a building before entry?

The firefighters should scan the outside of the building before entry because there may be factors that could affect with the rescue and it is also needed in order to locate possible escape routes when the firefighter has entered the house or building in order to determine which place to go and if it is safe.

if you know your abc's you should be able to get your answer or just use google