The principal of a South Side elementary school has retired amid an investigation into a 9-year-old being forced to leave the building when it was bitterly cold outside.

A video that showed Fiske Elementary Principal Cynthia Miller looking on as a school security guard shoved the boy out of the school was made public as part of a lawsuit filed earlier this month against Miller and Chicago Public Schools by the family of the boy.

Miller retired Friday from her role at Fiske Elementary, according CPS spokesman Michael Passman.

In a letter sent to Fiske parents Monday announcing her retirement, Miller stated: “While it has been an incredible privilege to lead this community of outstanding students and educators, I have decided to pursue other options.”

“This is not an easy decision, but as I reflect on my career path, I feel it is the right choice for me at this time.”

In the video, which was recorded March 26 on a school surveillance camera, a security guard can be seen yanking and shoving the boy, who was in fourth grade, toward an exit as Miller and a school counselor looked on.

The school, 6020 S. Langley Ave., is a few blocks southwest of the University of Chicago Medical Center in the Woodlawn neighborhood.

Minutes earlier, the boy had been in a fight but was not the instigator, according to the suit.

After the boy was ejected from the building, school staff called 911 to report him missing, according to the suit. And school staff called 911 a second time minutes later to request an ambulance be sent because the fourth-grader had been scratching, biting and kicking, according to the suit.

“They lied,” family attorney Dan Herbert said at a news conference Oct. 1 where he shared the video and announced the lawsuit.

A police officer arrived and found the boy, who’d sat down outside the school and was crying after finding every door to the school was locked, Herbert said.

The video prompted CPS to open an investigation into the matter and remove the security guard from his position at the school.

After the incident, the boy’s mother, Yvonne Pinkston, got a call from school staff telling her to come to the school, but she was in class at Purdue University.

The boy’s grandfather, Billy Pinkston, a Chicago police officer, also got a call and arrived at the school a short time later.

“I couldn’t believe it,” he said. “It was 40 degrees that day, 40 degrees outside. No coat, you know. Who does that to a child?”

The boy has enrolled in a different South Side school and is doing well but receives regular counseling due to his time at Fiske, his family said.

The 9-year-old was bullied soon after he transferred to the school after moving from Lafayette, Indiana, to live with his grandparents on the South Side, Herbert said.

Herbert said school officials came to see the boy as a problem child because he continually complained he was being bullied, and viewed his family, who also complained, as a problem as well.

“This would not have occurred on the North Side of Chicago. It would not have occurred in my neighborhood,” Herbert said.