NEW YORK - Lights went out Saturday night in the Empire State Building, the United Nations Headquarters and other landmark buildings and restaurants around New York, where electricity rarely goes off, for the "Earth Hour," a global call for action to combat climate change. The move emphasizes the event's potential to show people how to conserve energy without sacrificing entertainment, said Darron Collins, managing director of the World Wildlife Fund, the organization that coordinates the event. "I think what people like about Earth Hour is that it is fun and it tries to tap into people's creativity," Collins said. Gigantic lighted signs on Times Square, including those of Coca-Cola, the Chase banking group and the Nasdaq stock exchange also went dark in the "city that never sleeps." The United Nations, whose building looks onto the East River in eastern Manhattan, pitched in, as did the city's main universities and some businesses open late. "It's a good reminder to everybody that we are in charge of our destiny," New York Mayor Michael Bloomberg said in a statement. Cities across the United States participated in the global campaign, including Washington, Chicago, Los Angeles, Dallas, Miami and Las Vegas. A billion people across the world were invited by the WWF to cut electricity for an hour Saturday in the symbolic gesture.