The Los Angeles County health department said on Tuesday "there may be an alternate explanation" for the death of a California teenager whose "early tests indicated a positive result for COVID-19."

Why it matters: The fatality rate for the novel coronavirus in the U.S. is highest among those over 85, the CDC found in a report issued last week — and no deaths among people under 19 years of age were reported in the U.S. as of March 18. The CDC will evaluate the case of the teenagers' death in Los Angeles County.

There have been 11 virus-related deaths in LA County as of Tuesday, and at least 40 in the state of California.

LA County health officials did not specify in a press conference whether the minor had underlying health conditions. Additional information about the case is pending further investigation, the department said.

What they're saying: "COVID-19 does not discriminate by age, race or income level, and what we are seeing in places like New York is indicative of what we should prepare to experience here," Los Angeles County Public Health Director Barbara Ferrer said on Tuesday when announcing the juvenile fatality, emphasizing that residents should practice social distancing.

"It is a reminder to everyone to take this seriously," California Gov. Gavin Newsom said at a Facebook live address. Newsom identified the deceased individual as a teenager.

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Editor's note: This article has been updated with more comment from the health department and Newsom.