There have been dozens of mass shootings in the United States in just the past five years, according to the Violence Project, which maintains a database of attacks in which at least four people were killed.
And before that, many more were seared into memories: San Bernardino, California, and Charleston, South Carolina, in 2015; Newtown, Connecticut, and Aurora, Colorado, in 2012; Virginia Tech in 2007, among them.
Each new attack is a reminder of all of the others that came before it, as the nation has been unable to curb an epidemic of gun violence that far outpaces other countries. The bleak reality of a list like this is that it leaves out so many more, in addition to the mass shootings in Boulder and the Atlanta area over the last week.
Aug. 4, 2019: An entertainment district in Dayton, Ohio
Armed with an AR-15-style rifle and body armor, a gunman killed nine people and wounded 27 others in 32 seconds in a bustling entertainment district before he was fatally shot by a police officer.
Aug. 3, 2019: A Walmart in El Paso, Texas
Just 13 hours before the Dayton attack, a gunman prowled the aisles of a Walmart in El Paso, a majority-Hispanic border city, killing 23 people and wounding about two dozen others.
Oct. 27, 2018: A synagogue in Pittsburgh
In one of the deadliest attacks against the Jewish community in the United States, a man shouting anti-Semitic slurs opened fire inside a Pittsburgh synagogue, killing 11 congregants and wounding six others. The gunman shot indiscriminately at worshippers for several minutes.
Feb. 14, 2018: A high school in Parkland, Florida
A 19-year-old man barged into his former high school about an hour northwest of Miami and opened fire on students and teachers, killing 17 people. The shooting prompted a wave of nationwide, student-led protests calling for tighter gun laws.
Nov. 5, 2017: A church in Sutherland Springs, Texas
A gunman wearing a ballistic vest and toting a military-style rifle stormed into a Sunday church service at a small Baptist church in rural South Texas and sprayed bullets into its pews. He killed 26 people, including nine members of a single family, and left 20 people wounded, many of them severely.
Oct. 1, 2017: A concert in Las Vegas
In one of the deadliest mass shootings in American history, a gunman perched on the 32nd floor of the Mandalay Bay Resort and Casino, smashed the windows of his suite with a hammer and shot at a crowd of 22,000 people at an outdoor country music festival. Fifty-eight people were killed and 887 suffered documented injuries, either from gunfire or while running to safety.
June 12, 2016: The Pulse nightclub in Orlando, Florida
A gunman who had proclaimed allegiance to the Islamic State terrorist group attacked a crowded gay nightclub, Pulse, in Orlando, killing 50 people and wounding 53 others. After a three-hour standoff following the initial assault, law enforcement officials raided the club and fatally shot the gunman.