Of all the areas in Chicago, the South Loop is by far one of the safest areas. Columbia increases the natural safety of the area by adding 24-hour campus security to our campus, and has security guards stationed at every building. If there is a crime committed on campus, every student is alerted (with respect to the victim) via e-mail so they can avoid the area or know the details of what happened.
As with every area in Chicago, safety is also up to the individual. There are places common sense will tell you not to go to at odd hours of the night. The CTA is located right on campus at the Harrison stop and the Roosevelt stop. Both of these stops are well-lit and completely safe throughout the day. At night, there is more of a risk, so most students shouldn't be travelling alone by train at night. Be smart, and you'll be just fine.