Military service followed—Lutosławski was trained in signalling and radio operating in Zegrze near Warsaw. He completed his "Symphonic Variations" in 1939, and the work was premiered by the Polish Radio Symphony Orchestra conducted by Grzegorz Fitelberg, and this performance was broadcast on radio on 9 March 1939. Like most young Polish composers, Lutosławski wanted to continue his education in Paris. His plans for further musical study were dashed in September 1939, when Germany invaded western Poland and Russia invaded eastern Poland. Lutosławski was mobilized with the radio unit for the Kraków Army. He was soon captured by German soldiers, but he escaped while being marched to prison camp, and walked back to Warsaw. Lutosławski's brother was captured by Russian soldiers and later died in a Siberian labour camp.