fire alarm system

[bunmi]

how does it work

[R1Geezer]

big noise

leave building

tada!

[bazwillrun]

you left out the bit about how the big noise start.

fire start big noise

how does fire start that starts big noise ?

something starts smouldering then burns !

how does something start smouldering ?

thats for the forensic people to work out.

how do the forensic people work it out ?

they look for evidence !

how do they lo.........................................................