The Hawk’s Nest Tunnel Disaster involved thousands of workers being exposed to silica dust, and many continued to get sick and die for years after the tunnel was finished. The project was run with total disregard for workers’ lives and safety.
Research:

Robert Moses and the Shaping of New York, Part 2
42:12

Robert Moses and the Shaping of New York, Part 1
41:59

SYMHC Classics: Eradication of Smallpox
43:25