Why we need to talk about gun violence affecting kids. Now.

More than 5,100 children were shot in 2020. Over 1,300 were killed. And thousands of families were left grappling with the trauma of one of America's most gruesome epidemics: Gun violence affecting children.

Last year was the deadliest year for gun violence in the U.S. in at least two decades, according to the Gun Violence Archive, a nonprofit data collection and research group that tracks gun violence using a combination of police statistics and media reports.

In 2020, more than 5,100 kids under 18 were shot — about 1,000 more than at any point since at least 2014, when the archive launched — and more than 1,300 died. The numbers of kids shot and killed both increased by more than a third from the previous year.

The youngest kids saw the greatest rise in fatalities. Nearly 300 children ages 11 and younger were killed in 2020, about a 50% increase from the year before.

The COVID-19 pandemic has made the situation even worse.

As of early September, firearm fatalities were up 13%, and more children and teens had been shot than at the same time last year, according to the archive.

►Read USA TODAY's full report: 5,100 kids shot. 1,300 killed. Gun violence affecting children erupted during COVID-19.

Public health professionals, violence interrupters and researchers say the rise is due to a confluence of factors exacerbated by the pandemic, resulting in higher rates of unintentional shootings, suicides and homicides with children caught in the crossfire.

USA TODAY spent time in three cities that have seen the most violence and some of the greatest surges — Chicago, St. Louis and Philadelphia — speaking with children and teens, their families, physicians, public officials and advocates.

The youth described the heartache of losing family and friends and outlined what they say needs to happen in the U.S. to turn the tide on the epidemic.

Jaylah Robinson, 17, lost her sister to a stray bullet last August. Seeing the rise in shootings in her hometown of Philadelphia has made the past year a challenge for her and her family.

"This is something that don't get better," she said. "It's just devastating. It's something you can't move past."

Read USA TODAY's full report on gun violence and how it's affecting America's children here.

This article originally appeared on USA TODAY: Gun violence and children: Why we need to talk about US epidemic