Question

in case of FIREbefore the fire Man uses water hoses they shurtoff the main electrical supply for the area explain why they do this

Answer 1

Because they use water to put off fire and putting water in electricql supply is very dangerous. There can be explosion also.

Main electrical supply is shut off for safety measures and to prevent accident from electricity.

Hope it helps.

Answer 2

they do this because water is a good conductor of electricity and if water is accidently poured on electrical appliance or switch the man involved in fire extinguishing get electrical shocks and fire is not stopped
hope this might help you