He died after a brief illness, his family told Agence France-Presse.
Mr. Radonjic (pronounced rah-DON-yich) was one of six Serbians who were convicted or pleaded guilty in 1979 in the bombing of the Yugoslav consul’s home four years earlier, as well as a plot to bomb a Yugoslavian club in Chicago. Like the others, Mr. Radonjic was said to have been motivated by hatred for the Yugoslav dictator Josip Broz Tito and his Communist government.
In a terrifying and bizarre twist to the case, on June 20, 1979, four days before his sentencing, the leader of the group, Nikola Kavaja, commandeered a jetliner just before it landed in Chicago from New York by threatening to blow it up with a homemade bomb. After freeing the other passengers and most of the crew members, Mr. Kavaja forced the remaining crew to fly back to New York, where he demanded and received another plane capable of flying him to Ireland. There, for reasons only he knew, he surrendered to the Irish police. Mr. Kavaja, who served 20 years in prison, died in 2008.
Mr. Radonjic served three years in prison while his co-conspirators received sentences of 3 to 12 years.
Born in Uzice, Serbia, then part of Yugoslavia, on May 17, 1943, Mr. Radonjic came to the United States in 1970. His father, a teacher, had been executed by Tito’s partisans during World War II.
Information about survivors was not available.
After arriving in New York, Mr. Radonjic found work as a parking lot attendant in the Hell’s Kitchen neighborhood on the West Side of Manhattan. He later managed to lease a parking lot on his own on West 49th Street, the first of several lots that he operated.
Upon his release from prison in 1982, Mr. Radonjic returned to Hell’s Kitchen and joined the Westies, a traditionally Irish-American gang.
But as more and more of the gang’s leaders went to prison in the late 1980s, he was able to exert increasing influence over its operations and form ties with the Gambino crime family.
After the ethnic conflicts and partition of Yugoslavia in the 1990s, Mr. Radonjic returned to Belgrade, where he opened several bars and casinos and became a close associate of the Bosnian Serb leader Radovan Karadzic, whom the United Nations is currently prosecuting in the Hague on genocide charges.