The U.S. electrical grid is a complex system of power plants, transmission lines, and local distribution networks that deliver power to homes and businesses. It comprises three major grids - Eastern, Western and Texas - which are divided into hundreds of smaller sections. A summary of how power flows on the system, who oversees it and what went wrong in the August 2003 blackout:
WASHINGTON (AP) - Scientists who sparked an outcry by creating easier-to-spread versions of the bird flu for research purposes want to try such experiments again using a worrisome new strain. This time around, the U.S. government is promising extra scrutiny of such high-stakes research up front.
NEW YORK (AP) - The U.S. electrical grid is better managed and more flexible a decade after its largest blackout but remains vulnerable to increasingly extreme weather, cybersecurity threats, and stress caused by shifts in where and how power is produced.
DETROIT (AP) - Nearly 51 hours after jumping into a lake near the Michigan-Canada border, a long-distance swimmer who calls himself "The Shark" finished his 22-mile journey to Detroit while hauling hundreds of pounds of bricks.
LOS ANGELES (AP) - In a rare diplomatic rebuke, President Barack Obama called off an upcoming Moscow summit with Russian President Vladimir Putin on Wednesday, sending a stern message of disapproval over Russia's harboring of National Security Agency leaker Edward Snowden.
INDIANA COMMUNITY HANDS OUT DRUG TESTING KITS: LAWRENCEBURG, Ind. (AP) - A southeastern Indiana school is distributing kits so parents can test their children for drug use.
RENO, Nev. (AP) - A biker gang leader was convicted of murder Wednesday in the 2011 killing of a Hells Angels member at a Nevada casino that authorities said was part of an orchestrated assassination plot to take out a high-ranking official of the rival group.
WASHINGTON (AP) - Smartphones don't make smart babies, an advocacy group declared Wednesday in a complaint to the government about mobile apps that claim to help babies learn.
ATLANTA (AP) - Higher blood-sugar levels, even those well short of diabetes, seem to raise the risk of developing dementia, a major new study finds. Researchers say it suggests a novel way to try to prevent Alzheimer's disease - by keeping glucose at a healthy level.
DES MOINES, Iowa (AP) - The allure of capturing the estimated $425 million Powerball jackpot had players in a buying frenzy Wednesday, further confirming a trend that lottery officials say has become the big ticket norm: Fatigued Powerball players, increasingly blase about smaller payouts, often don't get into the game until the jackpot offers big bucks.
FORT HOOD, Texas (AP) - On the first day Maj. Nidal Hasan went on trial in a fight for his life, he claimed responsibility for the 2009 shooting rampage at Fort Hood. He posed no questions to most witnesses and rarely spoke. On one of the few times he did talk, it was to get on the record that the alleged murder weapon was his, even though no one had asked.
LOS ANGELES (AP) - Coastal waters off California are getting more acidic. Fall-run chinook salmon populations to the Sacramento River are on the decline. Conifer forests on the lower slopes of the Sierra Nevada have moved to higher elevations over the past half century.
NEW YORK (AP) - Publishers who have settled an electronic book pricing dispute with the federal government objected Wednesday to penalties the government wants to impose on Apple Inc., saying it will hurt publishers rather than the personal electronics giant.
North Bend, Ore. (AP) - David Wonnacott qualified for a tattoo license on July 5 and wasted little time establishing a business in a small, coastal Oregon community. Problem is, police said, he did it with a gun.
SECAUCUS, N.J. (AP) - The Children's Place has stopped selling a T-shirt that sparked complaints of sexism.
SALT LAKE CITY (AP) - Two Utah men removed from their Boy Scout leadership positions after a viral video showed them toppling an ancient rock formation pleaded guilty to misdemeanor charges Tuesday and avoided jail time.
WASHINGTON (AP) - Some of America's best cancer hospitals are off-limits to many of the people now signing up for coverage under the nation's new health care program.
GRAND CANYON NATIONAL PARK, Ariz. (AP) - Authorities investigating the death of a Texas man at Grand Canyon National Park believe he fell about 350 feet from the canyon's edge after trying to retrieve something, possibly a hat.
MOSCOW (AP) - In a gilded Kremlin hall used by czars, Vladimir Putin redrew Russia's borders Tuesday by declaring the Crimean Peninsula part of the motherland - provoking a surge of emotion among Russians who lament the loss of empire and denunciations from Western leaders who called Putin a threat to the world.
SEATTLE (AP) - A news helicopter crashed into a street and burst into flames Tuesday near Seattle's Space Needle, killing both people on board, badly injuring a man in a car and sending plumes of black smoke over the city during the morning commute.
WASHINGTON (AP) - Fourteen men were charged with operating an online child exploitation network that investigators said preyed upon hundreds of boys across the United States and overseas, authorities announced Tuesday.
MIAMI (AP) - Justin Bieber claimed after a shaky sobriety test in Florida that he was suffering from a hairline fracture in his right foot and made condescending comments to officers, according to a Miami Beach police document released Tuesday.
EFFINGHAM, Ill. (AP) - A southern Illinois man pleaded guilty Tuesday to first-degree murder in the 2013 stabbing death of his 7-year-old niece.
NEW YORK (AP) - Wal-Mart plans to start buying used video games from shoppers at stores in a move that goes after the bread-and-butter business of GameStop.
NEW YORK (AP) - Organizers of the fast-food protests for higher pay on Tuesday shifted their attention to another issue: "wage theft."
SALT LAKE CITY (AP) - A Mormon women's group pushing for gender equality was informed Monday that its members won't be allowed to protest on church property at the faith's upcoming conference.
ACAMPO (AP) - A San Joaquin County man who spoke of wanting to bomb the Los Angeles subway system was arrested near the Canadian border in Washington state and charged with attempting to travel to Syria to fight alongside Islamic extremists, federal prosecutors said Monday.
KUALA LUMPUR, Malaysia (AP) - Officials have revealed a new timeline suggesting the final voice transmission from the cockpit of the missing Malaysian plane may have occurred before any of its communications systems were disabled, adding more uncertainty about who aboard might have been to blame.
WASHINGTON (AP) - Unsuccessful with previous threats, the United States and its European allies stepped up their pressure on Russia to end its intervention in Ukraine on Monday by imposing the most comprehensive sanctions against Russian officials since the Cold War.
NEW YORK (AP) - A weekend of St. Patrick's Day revelry and tensions over the exclusion of gays in some of the celebrations culminated Monday in New York, where the world's largest parade celebrating Irish heritage stepped off without the city's new mayor and Guinness beer amid a dispute over whether participants can carry pro-gay signs.