WESTWEGO, La. -- A teen has been arrested after deputies say he told them he accidentally shot his sister, killing her early Friday morning.

Deputies said it happened around 12:30 a.m. in the 9200 block of East Claiborne Parkway in unincorporated Westwego.

According to the Jefferson Parish Sheriff's Office, the grandmother of the teens said her 15-year-old grandson ran into her room in a panic, saying he accidentally shot his sister in the head.

Deputies said they found the 14-year-old girl lying on the bedroom floor. She was brought to an area hospital, where offcials said she later died.

When investigators asked the teen how he got the gun, he reportedly told them he bought it on the street for "protection." JPSO said the grandmother told them she had no idea her grandson bought a gun.

Officials said a 9mm, semi-automatic gun was found in the victim's bedroom. An extra magazine for the firearm was also found in the 15-year-old's bedroom.

The teen was booked with negligent homicide and brought to the Jefferson Parish juvenile center.