One Tennessee family was met with tragedy Monday when their 7-year-old son was killed by his 8-year-old brother with a gun their mom left in her purse after she left the two alone in her van when she went to the store.

The shooting occurred just before 3:00 p.m. when the mother left her four children unattended in a Crossville, Tenn., parking lot as she went to a Verizon store where she and her significant other had stopped to pay a bill, reported NBC's Tennessee affiliate WBIR-TV. The 8-year-old the loaded handgun, a Taurus ACP .830, inside his mother's purse and tried to unload it, but it discharged instead, striking his brother in the head.

"The child removed the magazine in an effort to unload the firearm. The firearm was accidentally discharged," police said in a press release.

Local police and Cumberland County Emergency Medical Services arrived at the store soon after to find the child not breathing and bleeding from the head. He was first transported to the Cumberland Medical Center, and then later to the University of Tennessee Medical Center where he died, according to Newsmax.

Authorities have identified the parents as Samantha Farley, 29, and Jacob Farley, 29, and the Cumberland County District Attorney General's Office and the Department of Children's Services are investigating the incident.

Once their investigation is complete, the case will be handed over to Cumberland County prosecutors who will determine whether criminal charges should be filed, according to Newsoxy.

In the meantime, Tennessee Department of Children's Services spokesman Rob Johnson revealed that the surviving boy, as well as two other girls - aged 9 years, and another 4 months - are in the custody of relatives.