One in three Los Angeles County residents have been infected with the coronavirus, according to new estimates by county scientists, an astonishing sign of how rapidly the virus is spreading in the hard-hit region.

The estimate, based on scientific modeling, means officials believe more than 3 million of L.A. County’s 10 million residents have been infected with the coronavirus, including nearly 13,000 who have died.

That’s more than triple the cumulative number of coronavirus cases that have been confirmed by testing. Officials have long believed that testing only captures a certain percentage of those who are infected because many with the virus don’t show symptoms or suffer only mild symptoms.

The rising number of those infected has actually slowed the pace of coronavirus transmission, as the virus is increasingly coming into contact with people who have survived the infection and likely developed immunity.

Read the full story on LATimes.com.