The accidental shooting happened in the family home on Sunday, March 12, at 8pm local time.
According to Mail Online, Harris County Sheriff Ed Gonzalez said the two girls were left unsupervised in a bedroom in the apartment as one parent thought the other was watching them.
There were also five adults – family members and friends – present in the apartment on Bammel North Houston Road, among which were the girls’ parents.
It is believed that the three-year-old found a loaded semi-automatic pistol and shot once, striking her four-year-old sister, the sheriff said.
The adults rushed into the bedroom after the single shot was fired to find the four-year-old unresponsive.
They secured the firearm and called the emergency services via 911. The toddler was pronounced dead at the scene.
Sheriff Gonzalez said, “It just seems like another tragic story of, again, a child gaining access to a firearm and hurting someone else and this time there was a fatal shot.”
“Our hearts are broken. Our deputies are pretty shaken up,” Gonzalez continued, noting that support personnel would be at the scene to assist the officers and family members.
“The community is impacted when a child loses their life in this way,” he said and added that the shooting was another avoidable gun death.
“We continue to send the message that this is very preventable.
“You’ve got to be sure you’re being a responsible gun owner, securing your weapons in a safe place. It’s got to be more than just telling young kids not to touch the weapons.
“You know, we’ve got to do a little more. We see far too many tragic situations like this unfold.”
The Harris County District Attorney’s Office will decide whether any of the adults will face charges based on the police investigation, which is still in the preliminary phase, according to Gonzalez.
Mail Online reports that advocacy group Everytown for Gun Safety analysed data on shootings so far in 2023 and found that there had been at least 58 unintentional shootings by children in the US, which resulted in 22 deaths and 37 injuries.
The group added that in 2022, there were at least 353 unintentional shootings by children, resulting in 156 deaths and 212 injuries.