A Woodstock High School student who sheriff’s deputies said planned “a Columbine” was behind bars Friday, charged with terroristic threats.

Lake Reynolds, a 17-year-old junior, allegedly posted a message Thursday night on Twitter that said, “Planning on pulling a Columbine tomorrow guys, be prepared!” a Cherokee Sheriff’s Office spokesman said.

The reference appeared to be to the April 1999 massacre at Columbine High School in Colorado in which two students gunned down 12 fellow students and a teacher before committing suicide. Two dozen others were injured in the attack.

In a letter to students and parents Friday, Woodstock High School Principal Bill Sebring said the threat was “subversive to good order and discipline in the school.”

“Although we did not find evidence of plans by anyone to actually conduct a terroristic event, we remain on alert,” Sebring said.

Woodstock parents became aware of the tweet and made multiple calls to school officials, who contacted the authorities, sheriff’s spokesman Jay Baker said in a statement.

Baker said Reynolds admitted to the tweet after he was pulled out of class. “He was not armed and there is no indication that Reynolds actually planned a ‘Columbine’ attack,” the spokesman said in a release. “However, he is being charged with the threat.”

“Students should be aware that social media threats made about violence at a schools, even when a hoax, will result in criminal charges in Cherokee County,” Baker said.

Reynolds was taken to the Cherokee Adult Detention Center, where he was being held on $11,200 bond.