CHICAGO (CBS) — A report of a violent intruder at Columbia College on Tuesday panicked several students, but it turned out to be a false alarm.

An alert was sent out in the journalism school around 11:30 a.m. on Tuesday. Students in a television production class saw the alert appear on school monitors.

College officials acknowledged it was a mistake, blaming a technical glitch. They intended to send out an alert informing students that the college was closing at 3 p.m. due to the snowstorm.

An automated alert about the intruder went out instead.

Students were tweeting about the incident as it happened.

The school is indeed closing early due to the Winter Storm Warning in effect until midnight.

Columbia security sent an email apology to faculty, staff and students, saying its “audio and video emergency notification system malfunctioned,” and that “We would have issued an immediate “all clear” message using the emergency notification system, however, because of the malfunction, we could not rely on the system to deliver the correct message.”