One student was killed and four others wounded when a gunman with an AK-47 assault rifle opened fire in a New Orleans, La., high-school gymnasium, Reuters reported April 14.

According to police, four suspects were arrested just blocks from the John McDonogh High School. Their ages range from 15 to 19.

The shooting was reportedly in response to the murder of a 19-year-old student from another area school on April 7.

Investigators determined that the gunman used a back alley to get around metal detectors and guards at the school. The fatally shot 15-year-old victim also had a loaded gun, a 9mm pistol, in his pants.