In 1950, a Bioweapon in San Francisco

Military Wikia

Operation Sea-Spray was a U.S. Navy secret experiment in which Serratia marcescens and Bacillus globigii bacteria were sprayed over the San Francisco Bay Area in California. 

Military test

From September 20 to 27, 1950, the U.S. Navy released the pathogens off the shore of San Francisco. Based on results from monitoring equipment at 43 locations around the city, the Army determined that San Francisco had received enough of a dose for nearly all of the city’s 800,000 residents to inhale at least 5,000 of the particles.[1][2][3]


On October 11, 1950, eleven residents checked into Stanford Hospital for very rare, serious urinary tract infections. Although ten residents recovered, one patient, Edward J. Nevin died three weeks later. Cases of pneumonia in San Francisco also increased after Serratia marcescens was released.[4][5] (That the simulant bacteria caused these infections and death has never been conclusively established. Nevin’s son and grandson lost a lawsuit they brought against the government between 1981 and 1983.[6]) The bacterium was also combined with phenol and an anthrax simulant and sprayed across south Dorset by US and UK military scientists as part of the DICE trials which ran from 1971 to 1975.[1][7]

The urinary tract outbreak was so unusual that the Stanford doctors wrote it up for a medical journal.[citation needed]

There was no evidence that the Army had alerted health authorities before it blanketed the region with bacteria. Doctors later wondered whether the experiment might be responsible for heart valve infections around the same time as well as serious infections seen among intravenous drug users in the 1960s and 1970s.[8]

Senate subcommittee hearings

In 1977 Senate subcommittee hearings the army disclosed the tests. Army officials noted the pneumonia outbreak in their 1977 Senate testimony but said any link to their experiments was totally coincidental. The army pointed out that no other hospitals reported similar outbreaks and all 11 victims had urinary-tract infections following medical procedures, suggesting that the source of their infections lay inside the hospital.[1]


In 1981 Nevin’s surviving family members filed suit against the federal government, alleging negligence. “My grandfather wouldn’t have died except for that, and it left my grandmother to go broke trying to pay his medical bills,” says Mr. Nevin’s grandson, Edward J. Nevin III, a San Francisco attorney who filed the case in U.S. District Court.

The lower court ruled that the government was immune from lawsuits. The Nevin family appealed the suit all the way to the U.S. Supreme Court, which declined to overturn lower court judgments.[1][9][10]

Start the Conversation

Your email address will not be published. Required fields are marked *