JACKSONVILLE, Fla. -- Police said that a school staffer found a young man's body at Forrest High School on Firestone Road Thursday morning, and police said he had killed himself.

Homicide detectives said the body of a teenager dead from a single gunshot wound was found outside the gym just after 7 a.m. Police were called and the school immediately went into a lockdown.

Forrest officials rerouted buses and activated security code yellow, meaning students could only enter hallways to change classes.

Police have not said if the victim was a student at the school or released his name and age. A gun was found near the body.

The apparent suicide comes months after the suicide pact of two 13-year-old girls at Landrum Middle. One of the girls died.

A local mother whose 15-year-old daughter committed suicide said that parents should talk to their children about suicide.

"As a parent, I taught my kids about drinking and driving, drugs, but I never talked to them about depression, about suicide," Pam Harrington said. "I wish I had been educated."

Harrington, who organized the Beth Foundation, a suicide prevention group named after her daughter, said habit changes that last more than two weeks should prompt parents into asking questions.

Indications that a teenager might be contemplating suicide include talking about death or wanting to die; giving away belongings; losing interest in appearance and hygiene; and sudden isolation from family and friends.

Harrington called teen suicide the silent killer and said now is the time to talk.

"We can't prevent every suicide, but there is so much that we can do," she said.

A lockdown of the Forrest campus ended by 8:30 a.m. and classes got under way. School officials said grief counselors were brought in to work with students.

The Beth Foundation and Survivors of Suicide of Northeast Florida are holding four different free programs next Monday through Thursday evening at Duval County library branches and Riverside Presbyterian Church.