guerrillas. They pretended to demand a trial of President Belisario Betancur for violation of the peace accords. During the operation led by security forces to retake the Palace, a large group of guerrillas, civilians, magistrates and soldiers lost their lives— at least 53 civilian casualties were registered, including several members of Colombia's Supreme Court of Justice. The siege has been catalogued as a holocaust and massacre by the Inter-American Court of Human Rights. Peace negotiations Navarro coordinated peace negotiations for this movement during President Betancur' government in 1984 and 1985. He was named head of the Commission to organize the National Dialogue, along with Vera Grabe, Alfonso Jacquin, Andrés Almarales and Israel Santamaría. Talks were broken off, truces failed and the peace process died. In May 1985, the talks collapsed after an attack in a cafeteria in the city of Cali, when a soldier threw a grenade that exploded 10 cm away from Navarro, who was severely wounded. The facial nerve that controls the left part the jaw was destroyed and he lost his left leg below the knee. M-19 received news that Navarro was to be attacked in the hospital, so he was evacuated to Mexico where the leg was amputated. He received a prosthesis in Cuba. Later, Carlos Pizarro carried out peace negotiations with the government of President Virgilio Barco. The peace agreement was on signed 11 March 1990. After signing the peace agreement, M-19 nominated its leader, Carlos Pizarro Leongómez to run as candidate for the presidency, but he was assassinated on a commercial flight from Bogotá to Barranquilla on 26 April 1990. After Pizarro's burial, the leaders of M-19 met and decided to continue with the peace process. They nominated Navarro for the presidency, who came in third in the balloting. Political life In the 2000s, M-19 entered a leftist coalition of parties called the Alternative Democratic Pole and Navarro became its Secretary General. Antonio Navarro has been mayor of the city of Pasto, Congressman of Colombia and was one of the three collegiate presidents of the Constituent Assembly of Colombia writing the Colombian Constitution of 1991. He has served as Colombian Minister of Health. In 2006, he ran for the presidency of Colombia, but lost to Carlos Gaviria in the party primaries. He then ran for the Senate and was elected. After he is elected governor of Nariño of the PDA. Later after the election