hi,
normally emergency services disconnect the battery when pulling people out of crashed cars with undeployed bags...
having said that newer air bag control systems have a small backup power supply in event of main battery failure...
having said that you can still deploy a bag by shorting the firing squib with a drill or something like that
(you occasionally hear of mobile phone / stereo installers down under with broken ear drums thinking 'oooh this pillar looks like a good place to drill to put the hands free mike or after market tweeter!)
anyway hope i haven't put you off but you need to checker with the dealer on the correct procedure to safe the airbag controller.
cheers skip