In 1950, San Francisco residents went about their normal lives — walking to work, sending kids to school, opening their windows, and breathing in the city’s famous fog — with no idea they had become part of a classified military experiment.

As part of Operation Sea-Spray, the U.S. Navy released bacteria off the coast of San Francisco to study how a biological attack might spread through an American city. The public was never warned. The test remained classified for decades. And shortly afterward, a rare cluster of infections appeared at a local hospital.

In this episode of Haunted Real Estate, Ashley introduces a new series on documented government experiments and explores the unsettling history of Operation Sea-Spray — a story about secrecy, consent, Cold War fear, and how a place can be haunted by decisions that were very, very real.

Sources:

National Academies, CDC, US Army and Senate testimony on open‑air biowarfare tests; reporting from KQED, Smithsonian Magazine, PBS American Experience; historical materials on Ohlone land and Mission San Francisco de Asís from NPS and Muwekma Ohlone sources.