A power blackout beginning the afternoon of Aug. 14, 2003, cascaded from northeast Ohio to seven other states and parts of Canada, reaching 50 million people. Some of the immediate and long-term effects:
THE DARK SIDE: Outages of various durations stretched across 9,300 square miles, leaving customers from Michigan to New England with intermittent phone service, no lights and no air conditioning in the summer heat. The blackout shut down more than 100 power plants, forced hospitals and prisons to operate on backup generators, and stranded people in elevators and on roller coasters. It caused transportation chaos as airlines canceled flights and much of New York City was immobilized.
HIGH AND DRY: Outages were reported along a 145-mile stretch of Lake Erie coastline. That created water shortages for about 1.5 million people near Cleveland, which had no power to pump its water up from Lake Erie.
TREE TRIMMING: Trees touching higher-voltage transmission lines were partly blamed by blackout investigators, and utilities began trimming vegetation more attentively along such lines. Occasionally it leads to legal disputes with residents protective of their greenery.
NEW RULES: The tree-trimming is among regulations mandated after the blackout to ensure reliability. The North American Electric Reliability Corp. now sets standards and tracks the performance of the larger grid.
RAPID RESPONSE: Grid operators now are better trained and use technology that allows them to monitor the system more closely and nearly in real time. Some operators have added new control centers.