CHARLESTON, S.C. (Reuters) - A 14-year-old South Carolina boy shot and killed his father then drove to an elementary school playground where he wounded two children and a teacher with a handgun before being tackled by a firefighter who held him for police, authorities said on Wednesday.

The suspect, whose name has not been released, was accused by police of fatally shooting his 47-year-old father, Jeffrey DeWitt Osborne, then driving a pickup truck about 2 miles (3.2 km) to Townville Elementary School where he crashed into a fence surrounding the playground.

After the teenager began shooting, volunteer firefighter Jamie Brock pinned him down while staff led children to safety inside the building, Anderson County emergency services director Taylor Jones told a news conference.

Police arrived within seven minutes of a teacher calling 911 to take the suspect into custody at the school in Anderson County, near the Georgia state line about 100 miles (160 km) northeast of Atlanta. The shooter never entered the building, said Chief Deputy Keith Smith.

Authorities do not know the motivation of the shooting but ruled out race as both the shooter and victims were white.

U.S. schools have taken added security precautions since 2012 when a gunman shot and killed 20 children and six educators at Sandy Hook Elementary School in Newtown, Connecticut.

Brock, a 30-year veteran of the Townville Volunteer Fire Department, was hailed on social media as a hero and credited with preventing another school massacre.

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“(He) was there in the hot scene and risked his life to mitigate this incident,” Jones said. “He just used enough force to take him to the ground.”

One of the victims, 6-year-old Jacob Hall who police say was shot in the leg, remained in critical condition, Greenville Health System spokeswoman Sandy Dees said.

The other boy and a female teacher were treated and released, said Ross Norton, a spokesman for AnMed Health Medical Center. The boy, who local media reported was 6 years old, was shot in the foot and the teacher in the shoulder, authorities said.

SUSPECT CALLED GRANDMOTHER

Anderson County Sheriff’s Office Captain Garland Major told reporters he did not know the relationship between the shooter and those wounded at the school.

Authorities said the suspect was home-schooled and called his grandmother who went to his home and found the boy’s father had been shot.

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“She could not make out what he was saying because he was crying and upset and so they went to the house ... and that’s when she discovered her son and called 911,” coroner Greg Shore told a news conference on Wednesday night.

Immediately after the shooting, armed officers guarded students as they were evacuated from the school and taken by bus to a nearby church, local media said. Television images showed police swarming the school, with some officers on the roof while others moved around the building.

Jamie Meredith, whose daughter is in kindergarten at Townville Elementary, told WYFF news that she panicked after getting word of the shooting. Her daughter is OK but described a scene of scared and crying children.

“I’m just scared,” Meredith said through tears as she was interviewed by WYFF. “I don’t even want her to go to school now.”

About 280 students attend the school.

The incident was the latest in a series of shootings at U.S. schools that have fueled the debate about access to guns in America.

Earlier this month, a 14-year-old girl shot and wounded a fellow student at a rural Texas high school and then died of a self-inflicted gunshot wound.

South Carolina Governor Nikki Haley is due to meet with law enforcement officials in the area this evening, Jones said.