A two-year-old boy has killed his pregnant mother after he accidentally shot her in the back at Norwalk, Ohio, in the United States.

The police said the boy found a loaded gun on a nearby nightstand adding that it was the woman that called after the incident happened around 1 pm last week Tuesday, CBS said.

Police Chief David Smith of Norwalk told reporters on Tuesday that he was one of the officers who responded shortly after the call on Friday after multiple calls to 911 from the woman. 

Smith identified the victim as 31-year-old Laura Ilg, stressing that the officers found her still conscious on her bedroom floor with a Sig Sauer Micro 9mm gun resting on the nightstand.

“She explained she was 33 weeks pregnant, and her 2-year-old just accidentally shot her in the back,” Smith said.

The victim was rushed to Fisher-Titus Medical Center for an emergency cesarean section, but doctors were unable to save the baby. The mother died three hours later, authorities said.

Smith said the house was full of safety features, but baby gates that were usually closed had been left open. 

CBS reported that the victim was doing laundry in the bedroom, which was usually locked, and apparently was not aware her toddler son had followed her before he started playing with the gun and it discharged, Smith said.

Police said a loaded shotgun and rifle were also found in the home. Smith urged families to lock up guns and never leave them loaded and unattended. No arrests have been made in the case.

“Trigger locks, gun safes, there are a million varieties, and they aren’t that expensive. At the very least, leave them unloaded,” he said.

“Words truly cannot express how heartbreaking this is, and we cannot imagine the pain and heartache,” the department said in a statement.

According to an online obituary, Ilg “always wanted to be a mother and wife.”

A non-profit organisation, Everytown for Gun Safety said unintentional shootings happen most often when children are at home. 

The organisation reviewed data from 2015 to 2022 and found that the highest number of unintentional child shootings per day occurred in the summer. 

At least 895 children aged 5 and under have managed to find a gun and unintentionally shoot themselves or someone else from 2015 to 2022, according to Everytown. 

Already this year, a 6-year-old boy shot his infant sibling twice in one incident. In June, a 3-year-old boy died after he accidentally shot himself in Tennessee, officials said. 

In May, a 4-year-old girl accidentally shot and killed another child in Illinois, authorities said. 

Another 4-year-old girl was critically injured after she accidentally shot herself in the head in Georgia; her father had left the loaded gun on the floor of their home, police said.