BRUSSELS — Serbia's ambassador to NATO was chatting and joking with colleagues in a multi-story parking garage at Brussels Airport when he suddenly strolled to a barrier, climbed over and flung himself to the ground below, a diplomat said.
By the time his shocked colleagues reached him, Branislav Milinkovic was dead.
His motives are a mystery. Three diplomats who knew Milinkovic said he did not appear distraught in the hours leading up to his death Tuesday night. He seemed to be going about his regular business, they said, picking up an arriving delegation of six Serbian officials who were due to hold talks with NATO, the alliance that went to war with his country just 13 years ago.
A former author and activist opposed to the authoritarian regime of Serbia's former strongman Slobodan Milosevic, he was outgoing, had a warm sense of humor and worked to reach out to keep good ties with ambassadors from other ex-Yugoslav countries, according to diplomats and acquaintances.
The diplomats, who spoke on condition of anonymity because they were not authorized to release details, said they knew of no circumstances — private or professional — that would have prompted him to take his own life.
But Milinkovic, 52, had mentioned to colleagues at diplomatic functions that he was unhappy at living apart from his wife, a Serbian diplomat based in Vienna, and their 17-year-old son.
One of the diplomats described the death to The Associated Press, saying she had spoken to a member of the delegation who had witnessed the leap from the 8- to 10-meter-high (26- to 33-foot-high) platform.
The diplomats all spoke on condition of anonymity because they are not permitted by foreign service regulations to speak publicly to the press.
Speaking in Brussels, Serbia's Prime Minister Ivica Dacic said that "Belgian police are investigating, but it's obviously a suicide. It's hard to figure out the motives or causes."
The death cast a pall on the second day of a meeting of NATO foreign ministers. Officials said they were shocked by the news of the death of a very popular and well-liked man.
NATO's Secretary General Anders Fogh Rasmussen said he was "deeply saddened by the tragic death of the Serbian ambassador."
"As Serbian ambassador to NATO he earned the respect and admiration of his fellow ambassadors," he said.
During the 1990s, Milinkovic was active in the opposition to Milosevic. After he was ousted in 2000, Milinkovic was appointed Serbia's ambassador to the Organization for Security and Co-Operation in Europe, or OSCE, in Vienna.
He was transferred to NATO as Serbia's special representative in 2004. Serbia is not a member of the military alliance, but Milinkovic was named ambassador after Belgrade joined NATO's Partnership for Peace program, which groups neutral states.
The move to join the NATO program had angered Serbian nationalists who are now in power. They have pledged the nation will never join because of the alliance's 1999 bombing campaign, during which it forced Milosevic's forces to withdraw from Serbia's southern province of Kosovo.
Milosevic was widely blamed for instigating the Balkan wars that followed the breakup of Yugoslavia, conflicts that claimed more than 100,000 lives and left millions homeless.
At NATO, Milinkovic worked to foster closer ties with the representatives of all five other nations that gained independence after the bloody 1991 breakup of the former Yugoslav federation into Bosnia, Croatia, Macedonia, Montenegro, Slovenia and Serbia.
Relations were still a politically charged when Milinkovic first arrived in Brussels, but they have since improved drastically and it is now routine for envoys to exchange information or provide other assistance.
Two months ago, when Croatia's ambassador to NATO was transferred to Moscow, Milinkovic organized a dinner for all five of his counterparts at which a band played music from all parts of the former federation.
He is survived by his wife and son.