Guns were No. 1 killer of children and adolescents in 2020, CDC data shows

There were 45,222 firearm-related deaths in the U.S. in 2020.

Firearms surpassed car accidents as the No. 1 killer among children and teens, according to startling new data released by the U.S. Centers for Disease Control and Prevention Friday.

As firearm deaths for all Americans reached a new peak in 2020 -- 45,222 -- researchers said the numbers were particularly troubling among people under 19 years old.

Gun deaths in that age group saw a 29.5% jump from 2019 to 2020, which was more than twice as high as the relative increase in firearm deaths seen in the general population, according to the CDC.

For the last 21 years, gun deaths were second to motor vehicle crashes as the leading cause of death among children and adolescents, however, the gap between the two categories has been narrowing since 2016, the CDC said.

The cause behind the surging gun deaths in America was largely due to firearm-related homicides, which saw a 33.4% increase in the crude rate from 2019 to 2020, the CDC said. Firearm-related suicides in the U.S. increased by 1.1% during that period, according to CDC data.

In a letter to the editor published in the New England Journal of Medicine Friday, CDC researchers couldn't provide a reason for the increase in gun deaths, but stated "the new data are consistent with other evidence that firearm violence has increased during the COVID-19 pandemic."

"It cannot be assumed that firearm-related mortality will later revert to pre-pandemic levels," the researchers wrote.

The researchers called for more investments in organizations and programs aimed at curbing community violence.

"The increasing firearm-related mortality reflects a longer-term trend and shows that we continue to fail to protect our youth from a preventable cause of death shows that we continue to fail to protect our youth from a preventable cause of death," they wrote.

Dr. Grace Cullen, an internal medicine resident at the Mayo Clinic in Rochester, Minnesota, and a member of the ABC News Medical Unit, contributed to this report.