Nearly a week after Nidal Hasan allegedly went on a shooting rampage at Fort Hood, questions swirl around reports of the Army psychiatrist's past communication with a radical Muslim imam. Did authorities, who had been aware of Hasan's contact with Anwar al-Awlaki, miss an opportunity to head off the deadly killing spree?

A prison official in southern Virginia says John Allen Muhammad, the sniper who terrorized the Washington, D.C., area with a young accomplice in 2002, seemed "quiet and relaxed" before being put to death by lethal injection Tuesday night.

Even though the country has become more pessimistic, President Barack Obama still enjoys the confidence of a majority of Americans. An Associated Press-GfK poll shows that he has an approval rating of 54 percent. But it also says the number of people who think the country is heading in the wrong direction has increased.

Transmission problems at a huge hydroelectric dam in Brazil caused a massive power outage Tuesday night, leaving millions in several major cities without electricity for hours. The lights have since come back on, but the incident is another black eye for the South American country set to host the 2016 Olympic Games.

British authorities say they stopped a United Airlines pilot from flying on Monday because he was intoxicated. Erwin Vermont Washington was charged in the incident and has since been released on bail. United spokeswoman Megan McCarthy says the 51-year-old was "removed from service" during an investigation.

A new study by Consumer Reports finds what it deems unhealthy levels of bisphenol A, or BPA, in a variety of canned foods. Although this preservative has been linked to diseases in animals, industry groups insist it is safe. Two recent measures in Congress are calling for a ban on BPA, and both the FDA and EPA plan to study the issue in coming months.

NASA marks the 400th anniversary of the telescope by releasing one of the most detailed images to date of the heart of the Milky Way. The image, a composite created by the Hubble and Spitzer space telescopes and the Chandra X-ray Observatory, will go on display at scores of planetariums, libraries and schools.

Researchers are ranking the 50 U.S. states according to which have the happiest residents. In general, they say, the states with wealthier, better educated and more tolerant residents are the happiest. Well-being is highest in the Mountain and West Coast states, followed by the Eastern Seaboard.