The first black African secretary-general and Nobel Prize winner Kofi Annan died at the age of 80 today.
Annan died this morning at a hospital in Switzerland. His foundation announced his death in a tweet saying he died after a short unspecified illness.
The United Nations flag at its headquarters in New York is flying at half staff to pay tribute to Annan.
Annan began his career in the UN in 1962. In 1997, he was elected to the organization's top post, a position he held until 2006. He was also awarded the Nobel Peace Prize for his work in revamping the organization in 2001.
Several politicians and organizations are sending their condolences including former President Barack Obama, who called Annan "a diplomat and humanitarian who embodied the mission of the United Nations."