NEW YORK, Dec. 4 (JTA) — Gerhart Riegner, who first alerted the world to the Nazi plan to exterminate the Jews, died of pneumonia Monday in Switzerland at the age of 90. Riegner was working for the World Jewish Congress in the summer of 1942 when he received intelligence information that the Nazis were planning to murder Europe´s Jews. On Aug. 8, 1942, he gave his cable to U.S. representatives in Switzerland. "Received alarming report" that the Nazis are discussing a plan "according to which all Jews in countries occupied or controlled by Germany, numbering 3-1/2 to 4 million, should, after deportation and concentration in east, be exterminated," the cable read. Riegner asked the U.S. government to pass the cable to Rabbi Stephen Wise, president of the World Jewish Congress. However, the State Department said it would not pass on cables from private sources. Instead, it checked with the Vatican and the Red Cross, which both said they didn´t know of any plans to exterminate Jews. By the fall of 1942, witness accounts had convinced State Department skeptics of the accuracy of Riegner´s report. But President Franklin D. Roosevelt didn´t create the War Refugee Board in an attempt to save Jews until January 1944. "Never did I feel so strongly the sense of abandonment, powerlessness and loneliness as when I sent messages of disaster and horror to the free world and no one believed me," Riegner later wrote. Despite these feelings — or perhaps because of them — Riegner devoted his life to Jewish causes and human rights. After World War II, Riegner was active in interfaith efforts and established the main Jewish group involved in dialogue with the Catholic Church, the International Jewish Committee for Interreligious Consultations. The running joke, said Elan Steinberg, the WJC´s executive director, was that Riegner, who never married, was so effective in dealing with church leaders because he was "a priest devoted to his church, just like them." He also was a key player in the early years of the United Nations, where for a time he headed the consortium of nongovernmental organizations. Riegner, a lawyer, was "instrumental is sensitizing the Jewish people to the human rights world at large, while sensitizing the human rights community to the issues of the Jewish people," Steinberg said. Riegner was born in Germany and immigrated to Switzerland in the 1930s. Yet he never became a Swiss citizen, highlighting the fact that he had been made stateless before the war — and that the Jewish people had suffered such atrocities because they had been stateless as well. Instead, he traveled with documents known as a laissez passer, which allows a person to travel from country to country without a passport. Riegner, who served as secretary-general of the WJC from 1965 to 1983, also was deeply involved in the immigration of North African Jews to Israel. Even if he had not sent his cable, "he would still have been a major figure in Jewish affairs," Steinberg said.