If One Storm Can Turn D.C. Dark For Several Days, What Would A Massive EMP Burst Do?

If One Storm Can Turn D.C. Dark For Several Days, What Would A Massive EMP Burst Do?: "A gigantic EMP burst over the entire country (caused by a massive solar storm or a very large nuclear explosion high in the atmosphere) could theoretically take down the entire national power grid.  Just try to imagine a world where nobody has any electricity, nobody can pump gas, nobody can use their credit cards or get any more money, where most vehicles won't start, where nobody has the Internet, where all cell phones are dead and where nobody can heat or cool their homes.  That is how serious an EMP burst could potentially be.  We are talking about an event that could be millions of times worse than 9/11."