Lieutenant General Jose Luiz Jaborandy Jr., head of the United Nations peacekeeping force in Haiti, died of a heart attack on board a plane from Miami to Brazil on Sunday, the U.N. said in a statement.
Jaborandy's death comes as the U.N. has been steadily drawing down the size of its force in Haiti and the impoverished Caribbean nation learns to rely on its own civilian police force.
Jaborandy was the second Brazilian commander of the U.N. Stabilization Mission in Haiti (MINUSTAH) to die while occupying the post.
In 2006, Lieutenant General Urano Teixeira Da Matta Bacellar was found dead at an upscale hotel in the country's capital with a self-inflicted gunshot wound to the head.
The Brazilian deputy chief of the overall U.N. mission in Haiti, Luiz Carlos da Costa, was also among a number of U.N. employees who died during an earthquake in January 2010 that devastated the capital, Port-au-Prince, destroying the U.N. offices.
In a statement the spokesman for U.N. Secretary-General Ban Ki-moon said Ban thanked Jaborandy for "his leadership and dedication to the cause of peace."
MINUSTAH was created in 2004 after Haiti's president Jean-Bertrand Aristide was forced out of office by an armed rebellion.
There are currently 2,338 blue-helmeted U.N. soldiers and 2,239 U.N. police, down from a peak of 13,300 soldiers and police, mostly from Latin America. Brazil makes up the largest contingent with about 850 Brazilian infantry plus military staff officers.
The U.N. helped maintain order during a violent transition back to democratic rule in 2006, and also played a crucial role in helping rebuild Haiti after the 2010 earthquake.
The U.N. force has come under fire for its alleged role in a cholera outbreak in October 2010 that has killed more than 8,600 people and infected over 707,000.
Jaborandy was appointed to head the mission in March 2014 and had served in the Brazilian Army since 1976.
He had a distinguished military career, serving as chief of staff of the Amazon Military Command and as parliamentary adviser to the Cabinet of the Army Commander.
He also worked for the U.N. Observer Mission in El Salvador in 1992, and the U.N. Observer Group in Central America (ONUCA) in 1991, according to his official biography.
The U.N. Special Representative in Haiti, Sandra Honoré, praised Jaborandy's efforts "to strengthen security in Haiti."