CBS News reports that the incident occurred on Sunday at around 8 p.m. local time when a 3-year-old girl shot her 4-year-old sister.

Five adults, including both children’s parents, were present in the home, but somehow the girls were alone in the bedroom.

“It appears that one parent thought the other parent was maybe watching the other children, when in fact, the two toddlers were left basically unsupervised inside the bedroom,” Harris County Sheriff Ed Gonzalez said during a press conference.

While in the bedroom, the 3-year-old came upon a loaded semi-automatic pistol and fatally shot her sibling. The adults came running when they heard the gunshot and found the 4-year-old on the ground. The adults secured the gun and called 911. The 4-year-old passed away in the home.

Now, prosecutors will decide if any adults will be charged for the accidental shooting, with Gonzalez saying it’s “very likely.”

“It seems like another tragic story of a child getting access to a firearm and hurting someone else,” Gonzalez added, calling the incident “very preventable.” He continued, “Everyone’s impacted, a community’s impacted when a child loses their life in this way.”

“You’ve got to be sure you’re being a responsible gun owner, securing your weapons in a safe place,” he said. “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.”