PITTSBURGH (AP) — Smack in the middle of where a D.C. developer hopes to build apartments on the Forest Hills-Chalfant border stands a small brick building adorned with a towering steel orb.

The four-story weathered object, which resembles a giant light bulb, is the genesis of the Westinghouse Electric Corp.’s foray into nuclear power — a 1937 van de Graaff particle accelerator, the world’s first industrial atom smasher.