Barack Obama and first lady Michelle laugh during the groundbreaking ceremony at the construction site of the Smithsonian National Museum of African American History and Culture.
Republican presidential hopeful Mitt Romney greets supporters during a campaign rally at the Tri-City Christian Academy in Chandler, Ariz. Romney held a campaign rally before participating in the Arizona GOP-CNN Debate.
Leonardo Zavattaro, Telam/AP
Firemen rescue wounded passengers from a commuter train after a collision in Buenos Aires, Argentina. A packed train slammed into the end of the line in Buenos Aires' busy Once station, killing at least 49.
Mohammed Huwais/AFP/Getty Images
Yemenis shout slogans as they demand the prosecution of Yemen's President Ali Abdullah Saleh, one day after elections which saw the end of Saleh's 33-year rule.
Mark Wilson/Getty Images
A U.S. Army Caisson team transports the casket of U.S. Army 1st Lt. David A. Johnson during a full honors burial service at Arlington National Cemetery in Virginia. 1st Lt. David A. Johnson died of injuries caused by an improvised explosive device while conducting combat a dismounted patrol in the Kandahar province of Afghanistan.
Rahmat Gul/AP
Protestors run as smoke rises from a burning truck during an anti-U.S. demonstration at a NATO military base in Jalalabad, Afghanistan. Anti-American demonstrations continued for a second day in Afghanistan over what the U.S. has said was the inadvertent burning of Muslim holy books at a NATO military base.
Chip Somodevilla/Getty Images
A competitor loses control of his pancake while racing during the Shrove Tuesday, or Mardi Gras, tradition at the National Cathedral in Washington, D.C. Pancake racers use frying pans to flip a cake three times while running approximately 100 feet against fellow competitors.
Spencer Platt/Getty Images
New York Archbishop Timothy Dolan joins fellow volunteers distributing food at a breadline at St. Francis Assisi on Ash Wednesday in New York City. Dolan, just returned from Rome, was among 22 Catholic churchmen who were elevated to cardinal Saturday by Pope Benedict XVI.
Binod Joshi/AP
72-year-old Nepalese Chandra Bahadur Dangi, who says he's only 22 inches tall, arrives at the airport in Katmandu, Nepal. Guinness World Records officials will be in Nepal this weekend to measure Dangi who hopes to be named the world's shortest man.
Antonio Scorza/AFP/Getty Images
A reveler of Beija-Flor samba school dances during the first night of Carnival at the Sambadrome in Rio de Janeiro. The Carnival street parties last for five days in Rio de Janeiro. This year a record-breaking 2.2 million people attended the parades.
