The Jefferson County Sheriff's Office is responding to reported threats at Columbine High School in Littleton, Colorado.
The sheriff's office said that there were threats reported to the high school.
Parents were advised to NOT pick up students and that they would not be released at 2:45 p.m.
The school is on lockout, meaning no one can come in or out.
Columbine was the site of a massacre on April 20, 1999, where Eric Harris and Dylan Klebold shot and killed 12 students and one teacher, injuring 21 others.
In addition to the shootings, homemade bombs were in several areas of the school.
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