 August 14th, 2003 didn't seem like a day for the worst blackout in North American history. The Cleveland Akron area was 87 degrees with no wind. The day's peak electric load wasn't close to record breaking. The Cleveland Grid's control area, managed by First Energy Corporation, was prepared for contingencies. Until mid-afternoon, the system remained within the standards of the North American Electric Reliability Council. Cleveland's control area was dependent on a few local power plants, especially Eastlake, a six-unit coal-fired facility, and the Davis-Bessie and Perry nuclear power stations. First Energy's operators imported power across high-voltage lines from three directions. West toward Michigan, East toward Erie, Pennsylvania, and Southeast toward Pittsburgh. Of note, Davis-Bessie was offline, reducing the grid's access to local generators needed to avoid voltage instability. At 1.13 p.m., Unit 5 at Eastlake tripped. At 2.02 p.m., a line in an adjoining area tripped as the transmission wire warmed, drooped, and contacted a tree. A half hour later, the same thing happened to a line between Cleveland and Pittsburgh. As the lines tripped, First Energy's operators were kept in the dark by a computer glitch in an alarm system. Then came the phone calls. At 3.35 p.m., Perry's nuclear plant operator reported a voltage spike on the unit's main transformer. Perry's operator called back again in a third time with a warning, something is wrong. The culprit, ultimately, was too many untrimmed trees. The early faults shifted loads to other transmission lines in the Cleveland-Pittsburgh corridor. They grew hotter, dipped, and contacted trees. Other lines tripped, and then between 3.45 and 4.05 p.m., transmission links to Pittsburgh and Erie were severed. Cleveland became a black hole, sucking power from Toledo, its last link to the outside power grid. A huge counterclockwise surge of more than 3,500 megawatts circled Lake Erie from generators in New York, New Jersey, and Pennsylvania, across Niagara Falls and Ontario, into Detroit, south to Toledo, and east to Cleveland. Nearly 500 generating units tripped. Around 4.10 p.m., blackouts formed from western Michigan, north to Hudson Bay, and east to New Jersey. The blackout was the second largest in world history. Over 50 million people were affected. Some areas of New York waited four days for power. About 100 deaths were blamed on it. Canada lost 0.7% of its gross domestic product. A blackout of this scale demanded answers. A post-blackout report noted that tree trimming practices needed to be upgraded across the industry. Upgraded operator training and mandatory grid reliability standards were also needed. The NRC too studied the blackout. Nine nuclear power plants had tripped due to grid instability. Their safety systems performed as designed, and on-site power was promptly re-established. The NRC's 1988 station blackout rule and licensee efforts to improve emergency power reliability had paid off. NRC risk modeling also found that core damage frequencies would be lower than previous estimates, due in part to improved diesel generator performance. Eventually, the Energy Policy Act of 2005 made previously voluntary reliability standards mandatory for U.S. electricity providers, and strengthened penalties for producers that did not meet them. The anniversary of the 2003 blackout is a reminder of the link between grid stability and nuclear power safety, as well as the need for cooperation. The New York Times compared the North American power grid to a canoe. It said, if just one person stands up, the boat will capsize. In this case, Ohio stood up.