BUENOS AIRES, Argentina — Patrick Baumann, the secretary general of basketball's world governing body who was seen as a potential IOC president, has died at the Youth Olympics. He was 51.

Baumann "unexpectedly succumbed to a heart attack" in Buenos Aires despite getting immediate medical help, the International Basketball Federation (FIBA) said Sunday in a statement.

"Basketball has lost a leader, an advocate and a friend and our thoughts are with Patrick's wife and two children at this tragic time," the Switzerland based FIBA said.

Baumann was FIBA's top administrator for 15 years, and an International Olympic Committee member since 2007.

"We can hardly believe this terrible news," IOC President Thomas Bach said in a statement. "We lose a young and sympathetic leader full of hope who was standing for the future of sport. Our thoughts are with his wife, his children and his family." NBA Commissioner Adam Silver also praised Baumann's dedication to the game.

"Nobody was more dedicated to the growth of basketball than Patrick," said Silver in a statement. "He loved the game and recognized its power to transform people's lives. He was also a dear friend and colleague who I attended countless games and events with over the past 20 years." Flags will be flown at half-staff at IOC offices in Buenos Aires and its home city of Lausanne, Switzerland. The IOC said a memorial will be held in the athlete village in Buenos Aires.

A lawyer from Switzerland, Baumann had taken an increasingly important role in Olympic circles.

He led an IOC panel evaluating the Paris and Los Angeles bids for the 2024 Olympics, and then took charge of overseeing preparations for the 2028 Los Angeles Olympics.

"Patrick was a partner and a friend," LA 2028 chairman Casey Wasserman said in a statement. "He is gone too soon and will be greatly missed." The IOC also appointed Baumann to the World Anti-Doping Agency executive board, and he was elected president of the global group of sports federations, known as GAISF.

At meetings last week on the sidelines of the Youth Olympics, Baumann updated IOC members on the Los Angeles Games and the 2020 Lausanne Youth Olympics. He was president of its organizing committee.

Baumann was key to developing the 3-on-3 urban version of basketball and pushing for its inclusion as an Olympic medal event.

He earned masters degrees from the Business School of the University of Chicago, and in sports administration from the University of Lyon in France.