 -- A teenager opened fire at an elementary school playground during recess in South Carolina on Wednesday, injuring two students and a teacher, but was brought down by a volunteer firefighter who jumped into the fray without being armed, officials said.

And investigators believe the incident is connected to the shooting death of a man nearby, who appeared to be the suspect's father.

A teacher placed a 911 call stating that a man was on the grounds at Townville Elementary School around 1:45 p.m., said Anderson County Emergency Service Director Taylor Jones and deputies from the Anderson County Sheriff's Office were on the scene within seven minutes, said Capt. Garland Major.

But a volunteer firefighter, who was among the first on the scene, "used enough force" to take the suspect, who was armed with a handgun, down, said Anderson County Sheriff's Office Deputy Chief Keith Smith. The suspect never entered the school, and the entirety of the incident happened on the playground during recess, Smith said.

A female teacher and a student were taken to AnMed Health Medical Center and have since been released. One child was airlifted to the Greenville Memorial Emergency Trauma Center, according to a Greenville spokesperson. He was still listed in critical condition as of 8 p.m., the hospital said.

In a statement, the boy's parents thanked the first responders who treated their son and asked for prayers and privacy.

The teacher was shot in the shoulder, while one student was shot in the foot and another in the leg, Major said.

Students from the school were evacuated in the wake of the incident. All of them have been accounted for, said Anderson School District 4 Superintendent Joanne Avery. School has been canceled for the rest of the week, and counseling services will be available, Avery said.

The Anderson County Coroner's Office is working on a death investigation about two miles away from the school that they believe to be related to the shooting, according to the Anderson County Coroner. That death appears to be a homicide, the spokesperson said.

A 911 call was placed by the 47-year-old man's family shortly after the school shooting was reported, said Coroner Greg Shore. When officers arrived, they found the man dead from a gunshot wound.

It is not known if there is a connection between the victims from the elementary school and the suspect, officials said.

The investigation into the two incidents are at the initial stages and will be "slow, methodical and meticulous," Major said.

Parents were seen crying and hugging their children as they picked them up from the school. Photos also showed students crying as they left on a school bus.

South Carolina Gov. Nikki Haley called the shooting a "tragedy."

"As we work together with law enforcement to make sure they have the support they need to investigate what happened in Townville, Michael and I ask that everyone across South Carolina join us in praying for the entire Townville Elementary School family and those touched by today's tragedy," Haley said.