Since the world is bonkers:

The University was informed by FBI counterterrorism officials today (Sunday) that an unknown individual posted an online threat of gun violence against the University of Chicago, specifically mentioning “the campus quad” on Monday morning at 10 a.m. Based on the FBI’s assessment of this threat and recent tragic events at other campuses across the country, we have decided in consultation with federal and local law enforcement officials, to exercise caution by canceling all classes and activities on the Hyde Park campus through midnight on Monday. All non-medical faculty, students and non-essential staff are asked not to come to the Hyde Park campus on Monday, or to remain indoors as much as possible if they are on campus.  Students in College Housing are asked to stay indoors and await direct communication from College Housing Staff.

My 13-year-old broke the news to us at dinner, via parents of friends.  She was excited!  Ah youth!