Taking Stock of Superstorm Sandy

Millions of Americans are feeling the brunt of one of the worst storms ever to strike the East Coast. Sandy is making its way across Pennsylvania toward Canada, after leaving a trail of destruction and death along the East Coast. We survey the damage, especially in lower Manhattan, where high winds and flooding have taken a serious toll.  How long will power out for millions of people?  Has Sandy demonstrated the vulnerability of the Grid? What about transportation — from flooded subways to international air travel?