California health officials say the first reported coronavirus death in the United States occurred on February 6, 2020 — three weeks before the Feb 29 case that was previously thought to be the first American death from the virus.

The patient in Santa Clara County, California died at home on Feb 6. The county medical examiner-coroner sent tissue samples to the CDC, which confirmed on Apr 21 that the patient was COVID-19-positive, according to the county’s Department of Health.

The county also received confirmation that two others deaths on February 17 and March 6 were also COVID-19-related.

“These three individuals died at home during a time when very limited testing was available only through the CDC. Testing criteria set by the CDC at the time restricted testing to only individuals with a known travel history and who sought medical care for specific symptoms,” the Santa Clara County said in a statement.

Until today, the first known COVID-19 death in the US was reported on Feb 29 in a Washington State man in his 50s.

Santa Clara County health officials say these may not be the last postmortum COVID-19 diagnoses. “As the Medical Examiner-Coroner continues to carefully investigate deaths throughout the county, we anticipate additional deaths from COVID-19 will be identified,” the agency said.

Image credit: National Institute for Allergy and Infectious Diseases. Novel Coronavirus SARS-CoV-2. Colorized scanning electron micrograph of an apoptotic cell (blue) heavily infected with SARS-COV-2 virus particles (yellow), isolated from a patient sample. Image captured and color-enhanced at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland.