If you see a downed power line, move at least 10 feet away from the line and anything touching it. The human body is a ready conductor of electricity.
The proper way to move away from the line is to shuffle away with small steps, keeping your feet together and on the ground at all times. This will minimize the potential for a strong electric shock. Electricity wants to move from a high voltage zone to a low voltage zone—and it could do that through your body.