[One] of the more intriguing [Project Moon Dust] reports is summarized here.
La Paz, Bolivia, 1979: A fireball fell with a whistling sound and exploded in the suburb of Rue Retiro. There was no impact crater, however. The two objects recovered were metal spheres, similar to copper, and “dark with light spots”. They were both about three feet (one metre) in diameter, three pounds (1.5 kg) in weight, and each had a nine-inch (230mm) hole in it. A Bolivian officer considered they seemed to be designed for space flight.