From the Model S Owners Manual:
If airbags have inflated, or if your vehicle has been in an accident, always have the airbags, seat belt pre-tensioners and any associated components checked and, if necessary, replaced by Tesla.
In a collision, in addition to the airbags inflating:
• Doors unlock and the door handles extend.
• Hazard warning lights turn on.
• Interior lights turn on.
• High voltage is disabled.
To restore Battery power, use the touchscreen to manually power off Model S (see page 4.6), then press the brake to power it back on again.
And in the First Responders Section:
If airbags have inflated, or if your vehicle has been in an accident, always have the airbags, seat belt pre-tensioners and any associated components checked and, if necessary, replaced by Tesla.
In a collision, in addition to the airbags inflating:
• Doors unlock and the door handles extend.
• Hazard warning lights turn on.
• Interior lights turn on.
• High voltage is disabled.
To restore Battery power, use the touchscreen to manually power off Model S (see page 4.6), then press the brake to power it back on again.
And in the First Responders Section:
Vehicle Owners
In the event of an accident, follow these instructions- Turn off the vehicle
Roadsters – Turn off the vehicle and remove the key
Model S – Does not turn off—simply press the "park" button on the end of the gear-selector stalk.
Tesla vehicles are electric and make no noise even when the powertrain is energized. - Non-emergency – Notify Tesla Roadside Assistance at 1-877-798-3752
Emergency – Dial 911 - See the Vehicle Ownership Card in your glove box for 24-hour Roadside Assistance information and towing instructions