HOUSTON -- A 16-year-old boy was charged with manslaughter Wednesday morning, accused by deputies of shooting his 15-year-old friend in the parking lot of a north Harris County apartment complex, KPRC Local 2 reported.

Investigators with the Harris County Sheriff's Department said three 15-year-olds and a 16-year-old, all Cypress Creek High School students, were sitting inside a pickup truck at the Rockwood Landing apartment complex on John F. Kennedy Boulevard near Aldine Mail Route shortly before 9:30 p.m. Tuesday when the 16-year-old boy pulled out a pistol.

"One of the males decided to pull out a pistol and was playing with it, thinking it was unloaded, from what we're told. He was playing around, pointing it, pulled the trigger and ultimately shot the 15-year-old friend," Harris County Sheriff's Department Sgt. James Parker told KPRC Local 2.

Adrian Hinojosa, the 15-year-old shot in the chest, died instantly. An official with the Cypress-Fairbanks Independent School District said the victim was a 9th-grade student and had a small circle of friends.

Authorities arrested the 16-year-old, who has not been identified, and charged him with manslaughter. He was taken to the Harris County Juvenile Detention Center.

"There are certain safety factors that you use with a firearm. If you always assume that it is loaded, then you are not going to have this type of accident," Parker said.

Investigators said they are questioning the two surviving 15-year-olds and other witnesses, and are trying to determine how the gun came into the 16-year-old's possession.

Deputies said none of the teens lived at the apartment complex but were visiting a friend who lived there.

CFISD released the following statement regarding the incident:

"Students and staff at Cypress Creek High School, together with the entire Cypress-Fairbanks community, are saddened by the death of a Cypress Creek High School student resulting from an incident that occurred late last night involving a firearm. We would like to express our heartfelt sympathy to the parents and family as they grieve the loss of this young man."

The district said grief counselors are at the school assisting students who needed help coping with the loss.