A threat posted on the Yik Yak social media website.

CHAPEL HILL, N.C. (WTVD) -- The UNC Department of Public Safety has made an arrest in its investigation into threats to campus safety made on social media. The threat was made early Thursday on the Yik Yak social media website.Police have charged 18-year-old Daniel Berkman Fischbeck, who lives on campus.The investigation began when someone posted the message "To all my friends, don't be in the Pit tomorrow at noon. Things will be getting a big explosive."The message set off a social media chain reaction with some students considering it a joke and others genuinely concerned for their safety given recent acts of violence at other college campuses.Fischbeck is charged with making a false bomb report to a public building.