Anja Niedringhaus, an award-winning photographer who spent her 20-year career covering conflict zones -- including the Balkans, Kuwait, Iraq, and Libya -- was killed while covering elections in Afghanistan on April 4. She was in a car in eastern Afghanistan with AP reporter Kathy Gannon when an Afghan policeman opened fire on them, killing Niedringhaus instantly. This is a look at Anja Niedringhaus's work.