In a nightmarish loop, children held each other as they escaped the latest school shooting.

This time it was at a private Christian school in Nashville Monday. The kids formed a daisy chain by holding hands as they were brought to a unification center to connect with their parents. They left behind three classmates who were killed along with three adults.

It was almost the exact scene that played out just over a decade ago at the Sandy Hook Elementary School in Newtown, Conn., where 20 students and six adults were slain by a crazed gunman.

“You can’t practice this,” Ed Davis, a former Boston police commissioner and security expert told the Herald. “In both cases, they are so young they will do what their teachers tell them to do. But this is unfathomable.”

Davis said his advice in such a shooting situation is simple — “run.” It can save your life, he said.

“Put as much distance as you can from you and the threat,” he said. “Be aware of your surroundings and just get as far away from the action as quickly as possible.”

It’s “pathetic,” he added, parents even need to coach their kids at all about surviving a school shooting. But with “military-grade weapons” being used, as is the case at The Covenant School in Nashville and Sandy Hook, there isn’t much choice.

“Just keep running!”

• A child weeps while on the bus leaving The Covenant School following a mass shooting at the school in Nashville, Tenn., Monday, March 27, 2023. (Nicole Hester/The Tennessean via AP)

• A group prays with a child outside the reunification center at the Woodmont Baptist church after a school shooting, Monday, March 27, 2023, in Nashville, Tenn. (AP Photo/John Bazemore)

• A man walks with children at the Woodmont Baptist Church after a school shooting at The Covenant School, Monday, March 27, 2023, in Nashville, Tenn. (AP Photo/John Bazemore)

• Adults walk with a child at a reunification center at the Woodmont Baptist Church after a shooting at The Covenant School, Monday, March 27, 2023, in Nashville, Tenn. (AP Photo/John Bazemore)

• A family leaves with their children from a reunification site in Nashville, Tenn., Monday, March 27, 2023. Officials say several children were killed in a shooting at Covenant School in Nashville. The suspect is dead after a confrontation with police. (AP Photo/John Amis)

• A police chaplain stands by as children from The Covenant School, a private Christian school in Nashville, Tenn., are taken to a reunification site at the Woodmont Baptist Church after a shooting at their school, on Monday, March, 27, 2023. (George Uribe via AP)

• Children from The Covenant School, a private Christian school in Nashville, Tenn., hold hands as they are taken to a reunification site at the Woodmont Baptist Church after a shooting at their school, on Monday, March, 27, 2023. (George Uribe via AP)

• Children from The Covenant School, a private Christian school in Nashville, Tenn., hold hands as they are taken to a reunification site at the Woodmont Baptist Church after a shooting at their school, on Monday, March, 27, 2023. (George Uribe via AP)

• NASHVILLE, TN - MARCH 27: School buses with children arrive at Woodmont Baptist Church to be reunited with their families after a mass shooting at The Covenant School on March 27, 2023 in Nashville, Tennessee. According to initial reports, three students and three adults were killed by the shooter, a 28-year-old woman. The shooter was killed by police responding to the scene. (Photo by Seth Herald/Getty Images)

• NASHVILLE, TN - MARCH 27: Children arrive at Woodmont Baptist Church to be reunited with their families after a mass shooting at The Covenant School on March 27, 2023 in Nashville, Tennessee. According to initial reports, three students and three adults were killed by the shooter, a 28-year-old woman. The shooter was killed by police responding to the scene. (Photo by Seth Herald/Getty Images)

• NASHVILLE, TN - MARCH 27: School buses with children arrive at Woodmont Baptist Church to be reunited with their families after a mass shooting at The Covenant School on March 27, 2023 in Nashville, Tennessee. According to initial reports, three students and three adults were killed by the shooter, a 28-year-old woman. The shooter was killed by police responding to the scene. (Photo by Seth Herald/Getty Images)

• An ambulance leaves of Covenant School, Covenant Presbyterian Church, in Nashville, Tenn. Monday, March 27, 2023. Officials say several children were killed in a shooting at the private Christian grade school in Nashville. The suspect is dead after a confrontation with police. (AP Photo/John Amis)

• Metro Nashville Police officers work at the scene near The Covenant School, a private Christian school in Nashville, Tenn., following a deadly shooting Monday, March 27, 2023. A female shooter wielding two “assault-style” rifles and a pistol also died after being shot by police. (Andrew Nelles/The Tennessean via AP)

• Metro Nashville Police officers gather near The Covenant School, a private Christian school in Nashville, Tenn., following a deadly shooting Monday, March 27, 2023. A female shooter wielding two “assault-style” rifles and a pistol also died after being shot by police. (Andrew Nelles/The Tennessean via AP)

• Children from The Covenant School, a private Christian school in Nashville, Tenn., hold hands as they are taken to a reunification site at the Woodmont Baptist Church after a deadly shooting at their school on Monday, March 27, 2023. (AP Photo/Jonathan Mattise)

• Metro Nashville Police officers gather near The Covenant School, a private Christian school in Nashville, Tenn., following a deadly shooting Monday, March 27, 2023. A female shooter wielding two “assault-style” rifles and a pistol also died after being shot by police. (Andrew Nelles/The Tennessean via AP)

• Metro Nashville Police cars escort evacuees from the school and church on schools buses as they leave Covenant School, Covenant Presbyterian Church, in Nashville, Tenn. Monday, March 27, 2023. Officials say several children were killed in a shooting at the private Christian grade school in Nashville. The suspect is dead after a confrontation with police. (AP Photo/John Amis)

• A police officer walks by an entrance to The Covenant School after a shooting in Nashville, Tenn. on Monday, March 27, 2023. (AP Photo/John Amis)

• Metro Nashville Police Department officers walk outside of Covenant School, Covenant Presbyterian Church, in Nashville, Tenn. Monday, March 27, 2023. Officials say several children were killed in a shooting at the private Christian grade school in Nashville. The suspect is dead after a confrontation with police. (AP Photo/John Amis)

• Law enforcement officers lead children away from the scene of a shooting at The Covenant School, a private Christian school in Nashville, Tenn., on Monday March, 27, 2023. (Jozen Reodica via AP)