Once again the rumors sprout again. So once again let's try to bury them.
First, Los Alamos was established AFTER the Chile Line had been abandoned, and therefore played absolutely no role in the building of the first atomic weapons.
Second, Los Alamos never was a bomb production facility except on a very, very limited experimental basis.
(The narrow gauge never was involved in weapons production. U235 was produced a Oak Ridge, TN and PU at Hanford, WA. Fabrication was done at Pentex in Amarillo, Tx, and at Sandia Laboratory in Albuquerque, NM, with fabrication of plutonium weapons done at Rocky Flats near Denver.)
So let's bury this urban myth once again, and perhaps it will stay buried.
CJ