Fifteen schools in the suburbs of Denver, including Columbine High School, were placed on lockdown Tuesday due to a "credible" threat of violence intercepted by local authorities.
The Jefferson County Sheriff's Department tweeted Tuesday afternoon that the lockdown included Columbine as well as 14 other schools in the mountainous region around Colorado's capital.
The lockdown came just days before the 20th anniversary of the mass shooting at Columbine High School.
We are currently investigating what appears to be a credible threat possibly involving the schools. Children are safe. Deputies are at the schools. Multiple schools are on lockout in Columbine area & Mountains. More details to come #JeffCo pic.twitter.com/LwS6VJKxdV— Jeffco Sheriff (@jeffcosheriffco) April 16, 2019
"We have placed #ColumbineHighSchool, #LeawoodElementary, @bhelementaryco and all mountain schools on lockout. No further information at this time," added a message from the county school system.
We have placed #ColumbineHighSchool, #LeawoodElementary, @bhelementaryco and all mountain schools on lockout. No further information at this time. Lockout means biz as usual inside buildings, entry/exit restricted. More on emergency procedures here: https://t.co/n6ogfznIp7— Jeffco Public Schools (@JeffcoSchoolsCo) April 16, 2019
On April 20, 1999, 12 students and one teacher at Columbine were killed by two students who later killed themselves. The attack is now considered the 12th deadliest mass shooting in modern U.S. history.
Tuesday's lockdown also came on the 12th anniversary of the mass shooting at Virginia Tech, in which 32 people were killed.