UPDATE: McMinn County deputies are investigating a shooting that killed a 17-year-old girl, Saturday. Officials say a 13-year-old boy unintentionally shot his older sister while he was attempting to unload a .223 rifle. 

The shooting happened inside of a home off County Road 278 near Niota. A 911 dispatcher talked the boy through performing CPR but his sister was pronounced dead on the scene. 

According to the Safe Tennessee Project's database of unintentional shootings this year, this is the 18th incident where a child has injured or killed someone due to access to an unsecured firearm. 

While deputies are trying to figure out what exactly happened, Sheriff Joe Guy is calling the incident very tragic. 

"It was very tragic and our prayers go out to the family," said Sheriff Guy. 

Director of McMinn County Schools Mickey Blevins said grief counselors broke the news to students in class Monday morning. The 17-year-old girl was a senior at McMinn County High School.  Channel 3 will not identify her until deputies officially release her name, but friends and teachers said she was known for her bouncy personality and smile. They said she will be missed dearly.  

Officials with the Safe Tennessee Project say Tennessee now ranks fourth in the nation for these types of accidental shootings. According to their records, 39 incidents since January have injured 23 children, 2 adults and killed 14 others. 

This is the second time a sibling in Tennessee has fatally shot another sibling in 2016. In January, an 8-year-old unintentionally shot and killed his 7-year-old brother with a gun found in their mother's purse. 

No charges have been filed at this time, deputies say their investigation is ongoing. 

PREVIOUS STORY: According to McMinn County Sheriff Joe Guy, a McMinn County teen died Saturday evening when a gun her brother was handling discharged.

The incident happened on County Road 278 near Niota around 845 PM. According to investigators, a 17 year old girl was at home with her 13 year old brother. The girl was sitting across the room as her brother was attempting to unload a .223 rifle when the rifle discharged. The 17 year old was struck once.  911 dispatchers attempted to assist the 13 year old with CPR, but the 17-year old was pronounced dead at the scene when responders arrived.

“It was very tragic, and our prayers go out to the family,” said Sheriff Guy.

The investigation is continuing. No charges have been filed at this time and names are not yet being released.