A person walks in Pioneer Courthouse Square, the site of an attempted bombing Nov. 27, in Portland, Ore. A Somali-born teenager, Mohamed Osman Mohamud was arrested and charged with attempted use of a weapon of mass destruction when the previous night he allegedly attempted to set off a car bomb during Christmas tree lighting ceremony in the park. It was reported that civilians were not at risk because the bomb was supplied to him by undercover federal agents and the explosives were inert.