(CNN) Another high school has turned into a scene of carnage, this time in western Kentucky.

Sixteen people were wounded, two of them fatally, after a shooter opened fire Tuesday morning at Marshall County High School, authorities said. Four others sustained various injuries.

A 15-year-old male student was arrested at the scene, Gov. Matt Bevin said. On Wednesday he was charged with two counts of murder and 12 counts of first degree assault, Marshall County Assistant Attorney Jason Darnall told reporters.

After the boy has a probable cause hearing and a detention hearing in the next two days, prosecutors will start the process of charging him as an adult, Darnall said.

A grand jury will meet on February 13, and the charges could change, Darnall said.

Authorities identified the slain victims as Bailey Holt and Preston Cope, both 15. Bailey died at the high school, and Preston died at Vanderbilt University Medical Center in Nashville, according to Kentucky State Police Commissioner Richard W. Sanders.

Bailey Holt and Preston Cope, both 15, were killed in the shooting.

Sanders said the suspect, armed with a handgun, walked into the school at 8:57 a.m. ET and started shooting. The first 911 call came two minutes later.

The victims ranged from 14 to 18, state police said. Fourteen were male and six female.

'Mom, there's been a shooting'

Some parents said their children told them the shooting started in the commons area before class, CNN affiliate WSMV reported

Missy Hufford said her son, Ethan, 15, ran into the gymnasium and out of the building through a side door. Then he called and asked her to pick him up, she said.

"I know when he called me, he said, 'Mom, there's been a shooting.' And I asked him if he was OK, and he said, 'I'm running,' " WSMV reported.

Misty Green said her daughter, Morgan, was in the commons area and "heard the 'pop, pop, pop' and initially got down, and then just realized what was going on, so they took out running out of the building as fast as they could."

"And teachers were grabbing kids up and helping them get into safe places. And helping them get outside and get to a safe location," Green told WSMV.

Junior Taylor Droke told CNN affiliate WZTV that she and a friend were running late and arrived as students poured out of the school.

"You could see students dropping their bags and just start running, pushing past each other," she said. "Everyone in cars started turning around and driving away. Kids were jumping the fence around the school and running through the woods."

Droke said she contacted her mother on FaceTime. Then she and her friend gave a ride to some students and loaned them phones to call their parents.

"Everyone just left their bags and ran, so people had no cell phones," Droke said.

Shot in the arm

Daniel Austin, a 17-year-old special needs student, was hospitalized. His parents kept calling his cell phone until someone in the emergency room picked up and said Daniel had been shot.

Daniel Austin, right, was wounded in Tuesday's shooting at Marshall County High School.

His mother, Andrea, rushed to the hospital, bewildered as to why this happened.

"Teachers love him. Students love him. I don't think (anyone) can say one bad thing about him," Andrea Austin said. "And that's not because I'm his mom. Everybody loves him."

Austin said her son was shot in the right arm, which might need to be amputated. She lauded the heroics of a fellow student and a teacher, who quickly scooped up Daniel after the gunfire stopped, rushed him to a car and drove him to a hospital.

Trooper thought deceased victim was his daughter

Sanders, the state police commissioner, said authorities are praying for the victims. The carnage was especially hard on first responders.

One of the first state troopers to arrive at the high school thought Bailey, the student who died at the school, was his daughter, Sanders said. The trooper's daughter had been dropped off at the school that morning, and she and the victim were wearing similar clothing, Sanders said.

"He had to go over to convince himself that that was not his daughter," Sanders said.

State police said six victims, including Preston, were taken to Vanderbilt in Nashville, about 100 miles away.

Among the injuries, three students were shot in the head, Dr. Oscar Guillamondegui, medical director of Vanderbilt's trauma intensive care unit, told reporters.

Three victims remained in critical condition at Vanderbilt late Tuesday, and one was in stable condition at the hospital, state police said.

"We're just as devastated as anybody would be," Guillamondegui said. "Luckily, we're trained and prepared."

Marshall County Schools Superintendent Trent Lovett asked the community to "wrap your arms around these families and around these students, as you always have."

"Together with the community, we will begin the long healing process within our schools. God be with us all," Lovett said.

The American flag is lowered to half staff near the spot 2 students were shot and killed & another 17 were injured during a school shooting at Marshall County High in Benton, Kentucky. #MarshallStrong pic.twitter.com/9pc57d3GBU — Nick Valencia (@CNNValencia) January 23, 2018

2 school shootings in 2 days

The violence in Marshall County, a rural area near the western tip of Kentucky, stunned the governor. Authorities have not provided a possible motive.

"It is unbelievable that this would happen in a small, close-knit community like Marshall County," Bevin said in a statement. "This is a tremendous tragedy and speaks to the heartbreak present in our communities."

Tuesday's attack came one day after another school shooting, in Texas.

On Monday, a 15-year-old female student was shot in the city of Italy, officials said. She was taken by helicopter to a hospital in Dallas. The suspect, a 16-year-old male, was "apprehended within minutes," city officials said.

The motive for that shooting also remains unclear.

At least two dozen prayer vigils and prayer circles were planned for Tuesday and Wednesday, according to the high school.

Giffords: 'Devastating news'

Former US Rep. Gabrielle Giffords, who survived a gunshot wound during a January 2011 assassination attempt in Tucson, Arizona, said the Kentucky shooting again demonstrates the need for stronger gun laws.

"The devastating news about the shooting in Kentucky this morning is the latest example, but just yesterday, while the nation's attention was focused on the government shutdown, school shootings were also reported in Texas and Louisiana," Giffords said in a statement.

"Our nation has experienced 13 mass shootings already this year, and it's only January. We will never accept these horrific acts of violence as routine."