Downed power lines are lethal.
As Cal DeBouvre explains, the voltage in a downed power line is high enough to push electricity through the dirt nearby. "If you spot a downed power line walk the other way and call the police immediately," he says.
If a line falls near you, keep your feet together and jump or shuffle away. If you take normal steps, you're at risk of conducting electricity in your body since the current can flow through both legs separately.