On July 28, 2003, a truck bomb exploded near the United Nations headquarters in Baghdad, Iraq, killing at least 22 people, including the UNs special representative, Srgio Vieira de Mello. The bombing targeted the UN as a symbol of international involvement in Iraq following the invasion earlier that year. The attack was one of the first in a series of increasingly violent actions against foreign nationals and organizations in Iraq. It marked a turning point in the post-war reconstruction efforts in Iraq. The tragedy highlighted the dangers of working in conflict zones.