A Lancaster, California, teenager thought to have died from COVID-19 last week was turned away from an urgent care clinic because he did not have health insurance, delaying medical attention at a critical time, the town’s mayor said Thursday.

“He didn’t have insurance, so they did not treat him,” mayor R. Rex Parris said in a video update.

“On Friday ... he was healthy, he was socializing with his friends. By Wednesday, he was dead.”

Parris did not reveal the name of the urgent care clinic, but said the teen was referred to Antelope Valley (AV) hospital, a public hospital north of Los Angeles.

“En route to AV Hospital, he went into cardiac arrest. When he got to AV hospital, they were able to revive him and keep him alive for about six hours,” Parris said.

While the Los Angeles County Department of Public Health initially said the 17-year-old had died of coronavirus, officials later backtracked. The Centers for Disease Control and Prevention in Atlanta is now looking into the case to determine a conclusive cause of death.

“On further investigation ... there were extenuating circumstances that pointed to an alternative diagnosis as well,” Los Angeles County Public Health Director Barbara Ferrer said at a press conference Wednesday.

The case could be the youngest known victim of COVID-19 in the U.S., which passed an alarming milestone on Thursday to become the country with the most confirmed cases worldwide.

According to Parris, the teen had been sick for “a few days” and had no previous health conditions.

The Los Angeles health department’s website has tracked 1,216 cases in Los Angeles County, while California is currently reporting more than 4,000 cases across the state.

Parris concluded his video with a message of solidarity: “This next few months, we have to be together. We have to be strong. And most importantly, stay home.”