Originally Posted by crazycal
I don't understand. I thought that if a power line came down and you were still in the car, you were OK until the power was shut off. Is that wrong?
That is the best advice. Electricity travels on the surface of conductors, so the metal passenger compartment acts as a "Faraday Cage" to pass any electrical current around
the passengers. Edit: That is also why you stay in a car during a thunderstorm, rather than get outside.
Rubber tires are only insulators at low voltages. Rubber is full of carbon, and carbon is a conductor, but not a good one like steel or copper. When a high-voltage line falls on a vehicle, I have heard of cases where the tires blow out from the current passing through them. The Faraday Cage can still protect the occupants until the power is shut off, as long as they do not freak out and try to exit the cage.
I don't know what happened in India. Perhaps the passengers had their arms out the windows, and touched the broken wires or the bus skin. The others might have been packed shoulder-to-shoulder, or tried to rescue the others and were shocked by the contact.
Rule number one is: Do not try to rescue someone who is actively being electrocuted until the power is cut off.