Christa Engles was shot in the head in November, 2014 by her 3-year-old son while changing her baby’s diaper in her Tulsa, Oklahoma home. The boy had found the 9mm semiautomatic handgun on a living room table.

Two months later, in Elmo, Missouri, five-year-old Corbin Wiederholt used a .22-caliber handgun he picked up off the headboard of the grandfather’s bed to shoot and kill his nine-month-old brother.

Not long after that, at a home in LeBleu Settlement, Louisiana, 3-year-old Alexis Mercer fatally shot herself with a handgun her father had just been cleaning. “It makes me angry,” Calcasieu Parish Sheriff Tony Mancuso told a local news outlet. “It makes my heart hurt. It’s just something that shouldn’t happen.”

It happens, on average, about every other day in the U.S. From September 2014 through September 2016, at least 295 children under the age of 13 injured or killed someone with a firearm, an analysis by The Trace of shooting data collected by the nonprofit Gun Violence Archive shows. More than 100 of the victims died.

Gun Violence Archive collects information on shootings using media reports and other public sources of information. There is no reliable federal source of information about shootings by young children.

Half of all the young child shootings examined by The Trace were self-inflicted. In all but a few instances, the shooter was a boy. In at least 113 cases, the child who pulled the trigger was three years old or younger.

The kids obtained these deadly weapons because an adult, usually a parent, left them loaded in a place where a child could find them.

The Trace examined cases of shootings by children under 13 because that is the age group that would have been covered under a safe storage law in Tennessee, proposed after an 8-year-old girl was fatally shot by her 11-year-old neighbor, who used his parents’ shotgun. The bill, defeated earlier this year after the National Rifle Association lobbied to quash it, would have given prosecutors explicit authority to bring criminal cases against adults if a child uses their unsecured gun in a shooting.

There are 14 states with negligent firearm storage laws similar to the one proposed in Tennessee. Of those, only four — Florida, California, Massachusetts, and Connecticut, along with the District of Columbia — allow prosecutors to charge adults whose unsecured guns are used by a child to shoot someone with a felony.

Only one state, Massachusetts, requires all firearms to be stored under lock and key.

DaMoni Troutman

Age 5
DaMoni was fatally shot by his 9-year-old half-brother, who found a loaded handgun in their paternal grandmother’s apartment in Indianapolis, Indiana, on November 9, 2014. A third child under the age of ten was home at the time. The gun belonged to DaMoni’s uncle, who was charged with criminal recklessness. Troutman’s mother, Brittney Rodriguez, said she did not know there was a gun at the apartment, and hoped other parents would learn from the experience, “because it can happen to anybody’s kids.”

Corbin Wiederholt

9 months old
Corbin Wiederholt, 9 months, was fatally shot in the head by his 5-year-old brother, who found his grandfather’s loaded .22-caliber revolver at his home in Elmo, Missouri, on January 19, 2015. When the gun went off, the older boy, who retrieved it from a locked cabinet, said to his mother, 26-year-old Alexis Wiederholt, “I’m sorry, Mom. I shot Corbin.” Wiederholt said she didn’t know her father kept a loaded gun in his home. “I told the boys they weren’t supposed to be in my bedroom where I keep the gun cabinet,” Porter said. “But like I said, boys will be boys.”

Makayla Manners

Age 4
Makayla shot herself in the face with an illegal semi-automatic handgun she found in her Yonkers, N.Y., apartment on May 25, 2015. She died four days later. A neighbor said her mother, 22-year-old Tantania Manners, was outside talking to friends on while the toddler’s aunt was watching her. Makayla’s neighborhood is “tough and unforgiving,” a local columnist wrote, “a place with a sad history of shootings, muggings and suspicious fires.”

Christopher Spruill

Age 4
Christopher was shot in the head and killed by his 5-year-old brother, who found their mother’s gun at their home in East Orange, New Jersey, on June 25, 2016. Police have not said how the older boy accessed the gun belonging to 22-year-old Itiyanah Spruill, who was arrested and charged with endangering the welfare of a child and weapons offenses. A judge allowed Spruill, who did not have custody of the children, to attend her younger son’s funeral while in custody.

Frank DuBois

Age 43
Frank was asleep in the living room of his Alma, Michigan, home on July 8, 2016, when his 7-year-old stepson found the keys to a locked gun case. The boy retrieved a rifle and fatally shot DuBois. A police spokesperson said the victim’s family owned weapons for hunting. “Why is a 7-year-old able to get to the keys while the family sleeps?” a neighbor asked a local news outlet. DuBois left behind a wife and five children.

Sincere Peek

Age 5
Sincere found a gun in on the second floor of his home in Madisonville, Ohio, on July 16, 2016, and shot himself with it. His older brother, Omarion McCrary, said he heard the gunshot and found his brother, whose heart was still beating. “I ran with him all the way downstairs, told my mama, ‘Call 911,’ ran to the neighbors,” he said. Peek died at the hospital. The boy’s older sister said she does not know who owned the guns or how her brother was able to get his hands on it. “I never would think I would feel this pain,” Feneshia McCrary said.

The safest ways to store guns in the home are through the use of trigger locks, lockboxes, and gun safes, Megan Moreno, a professor in adolescent medicine at the Seattle Children’s Hospital, wrote last year in JAMA Pediatrics. Moreno also recommended storing ammunition separately from the weapon. “‘Hiding guns from children does not work,” she warned.

[Interactive by Upstatement; Photo illustration by Joel Arbaje]