Central High School in Carrollton, Georgia

CARROLLTON, Georgia (CNN) -- A student was killed and her boyfriend was wounded in a shooting Friday at Central High School that may have been an attempted murder-suicide or double suicide.

The Associated Press reported that the girl died at Tanner Medical Center, while the boy was airlifted to Crawford Long Hospital in Atlanta, about 50 miles away. The extent of his injuries was unclear.

The shooting in a rest room of the science wing of the high school happened 15 minutes after classes started. The victims were discovered by a teacher, authorities said. Police said a .22-caliber pistol was used.

A student leaves after the shooting

"It's a boyfriend-girlfriend situation," said Carroll County Sheriff Tony Reeves. "Apparently there were problems between them."

School was closed for the day, and students were sent home by bus or waited for their parents to pick them up. Many were still at the school two hours after the incident.

The school has an enrollment of about 900.

The Associated Press contributed to this report.