As gunfire ripped through America in an unprecedented 24 hours, a bleak milestone in a nation pocked by gun violence was marked: There have been 251 mass shootings in 2019, according to the Gun Violence Archive.
A shooting spree early Sunday at an entertainment district in Dayton, Ohio – which left at least nine dead and more than two dozen injured – notched an even darker statistic: It occurred on the 216th day of the year, meaning there have been more mass shootings than days so far this year.
That incident followed a rampage Saturday at a Walmart jammed with back-to-school shoppers in El Paso, Texas, that left 20 dead and 26 injured.
The two massacres became the nation's latest mass shootings as defined by the archive, a not-for-profit organization that provides online public access to information about gun-related violence.
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El Paso updates: Latest news about the mass killing of 20
The archive categorizes mass shootings as incidents in which four or more people were shot or killed, not including the shooters. This year, more than 520 people have died in mass shootings and at least 2,000 have been injured, according to the data.
The bloody 24 hours came in a particularly painful week: Two people were shot and killed at a Walmart store in Southaven, Mississippi, south of Memphis on Tuesday, and three people were killed by gunfire last Sunday at the Gilroy Garlic Festival in Northern California.
And the violence follows two other high-profile shootings this year.
A longtime city worker opened fire in a building that houses Virginia Beach government offices May 31, killing 12 before he was gunned down by police.
On Feb. 15, an employee at a manufacturing plant in Aurora, Illinois, opened fire during a disciplinary meeting where he was dismissed. Five people died at the suburban Chicago plant before he was killed during a shootout with police.
Contributing: Olivia Sanchez, USA TODAY
This article originally appeared on USA TODAY: Dayton, Ohio, shooting marks 251 mass shootings in 216 days