When von Braun, a Nazi, surrendered himself to the United States, he lead US scientists to a stash of V2 rockets. The U.S. imported the rockets and retooled the pieces at a New Mexico launch site in an effort to harness the technology. In 1947, the army's third launch on a V2 nearly caused an international incident. A flaw in the guidance system had the rocket turn south, fly over El Paso, Texas, cross the border, and crash into a rocky knoll about three and a half miles from downtown Juarez, Mexico. It shook buildings, broke windows, and stopped the clock in the sheriff's office, but no one was hurt. The technology is better understood these days.