Li Du looked at the soldiers and suddenly realized: It wasn't because of Godzilla and Big Quinn that the others stayed away. It was because they knew this was the Air Force's territory!
Tucson was one of the US military bases, and Davis-Monthan Air Force Base was located here too. It was probably due to the development of the manufacturing industry. People knew that Houston was the "Space City," and Tucson was known as the "Astronomy Capital of the World."
There were many businesses manufacturing astronomy machines, and they were very close with certain high-tech industries making missiles, parts of aircraft, calculators, electronic equipment, optical instruments and so on.
In the 1950s, Hughes Aircraft Company set up a branch for managing missile systems and it was the largest factory for manufacturing missiles in 1957.