A fallen tree blocks one lane of traffic on 13th Street NW in the Logan Circle neighborhood of Washington, Saturday, June 30, 2012. Violent evening storms following a day of triple-digit temperatures wiped out power to more than 2 million people across the eastern United States. (AP Photo/Pablo Martinez Monsivais)

Photo by: Pablo Martinez Monsivais

A fallen tree blocks one lane of traffic on 13th Street NW in the Logan Circle neighborhood of Washington, Saturday, June 30, 2012. Violent evening storms following a day of triple-digit temperatures wiped out power to more than 2 million people across the eastern United States. (AP Photo/Pablo Martinez Monsivais)