BAGHDAD (AP) - A U.S. soldier opened fire at a counseling center on a U.S. base Monday, killing five fellow soldiers before being taken into custody, the U.S. command and Pentagon officials said. The shooting occurred at Camp Liberty, a sprawling U.S. base on the western edge of Baghdad near the city's international airport and adjacent to another facility where President Barack Obama visited last month. White House spokesman Robert Gibbs called the shooting a "terrible tragedy" and said Obama planned to meet with Defense Secretary Gates later in the day to discuss the matter.