Robert Toombs, 62, a veteran NBC News producer whose assignments spanned the globe from southeast Asia to the United Nations, died July 23 in New York of a heart attack.He joined NBC in 1961 as a newswriter and from 1971-1973 served as bureau chief in southeast Asia. He later worked in NBC’s Beirut bureau. Back in the United States in the 1980s, he was a field producer in the Northeast bureau and an editor on the foreign desk in New York. He retired from NBC in 1990 but was working at U.N. headquarters on contract for NBC News. Survived by his wife, Nancy, a daughter and brother.