The University of Colorado Boulder ordered all students, faculty and staff to shelter in place on Monday evening after police reported an unspecified threat near Norlin Library at the center of the main campus. Campus police evacuated Norlin Library and the nearby Sewall Hall residence facility and advised the public to avoid the area while officers investigated. No details about the nature of the police activity or potential injuries were immediately released. The university said additional information would be provided once the situation is resolved.