Soon after his experimental Washington station signed on, DuMont began experimental coaxial cable hookups between his laboratories in Passaic and his two stations. It is said that one of those broadcasts on the hookup announced that the U.S. had dropped an atomic bomb on Nagasaki, Japan, on August 9, 1945. This was later considered to be the official beginning of the DuMont Network by both Thomas T. Goldsmith, the network's chief engineer and DuMont's best friend, and DuMont himself. Regular network service began on August 15, 1946, on WABD and W3XWT. In November 1946, W3XWT was granted a commercial license and became WTTG, named after Goldsmith. These two DuMont owned-and-operated stations were joined by WDTV (channel 3) in Pittsburgh on January 11, 1949.