(David Zalubowski/Associated Press)LITTLETON, Colo. — The Latest on a lockdown at Columbine High School and other Denver area schools (all times local):4:50 p.m.Colorado Gov. The Department of Public Safety urged schools urged schools to tighten security, and more than 20 put lockdowns in place. ___4:10 p.m.All schools in the Denver area are being urged to tighten security after what appears to be a credible threat caused a lockout at Columbine High School and more than 20 other schools in the area. ____2:55 p.m.Students are leaving classes after tightened security at Columbine High School and over 20 other Denver-area high schools after a lockdown caused by a possible threat. Authorities say tightened security at Columbine High School and about a dozen other Denver-area schools is related to an FBI investigation.

Source: Washington Post April 16, 2019 20:35 UTC