Since I'm a librarian, the first thing that comes to mind is a list of resources on trauma and grieving. It won't be complete or comprehensive, but I hope this helps someone.
First is SCSU's Counseling Services. Most colleges and universities have some sort of counseling program, and people should not be shy about taking advantage of them. They can also given referrals to local services for things that they aren't equipped to handle. Many programs have excellent advice on their websites, as well, like Coping with Trauma. I should also mention that campus police services on many campuses have programs ranging from self defense to bioterrorism drills. SCSU's University Police has this advice for dealing with a "Hostile Person Incident".
Second would be federal resources. In the US, we have the National Institutes of Mental Health and the National Mental Health Information Center. NIMH (yes, as in the rats) has a guide to Coping with Traumatic Events. NMHIC has Coping with Traumatic Events Related Links, covering a wide range of circumstances and needs. Other governments have similar agencies, often under the auspices of the military (war-related post traumatic stress disorder has been the starting point for much stress and trauma related research.)
There are a wide range of non-governmental sites with information on trauma and grieving. The American Psychological Association covers Managing Traumatic Stress. HelpGuide.org has information on emotional trauma and grieving. Many organizations set up sites on trauma after 9/11 and Hurricane Katrina. Not all the links will be appropriate, or still active, but the resources should be similar to those needed now.
There are few general university-level programs, like Security On Campus. This site is more about individual crimes (specifically rape) but has good general advice like the Security Tips. Most programs that specifically deal with colleges and universities are aimed at a specific campus. The American Psychological Association has Tips for College and University Students: Managing Your Distress in the Aftermath of the Virginia Tech Shootings.
If you are dealing with children upset by the tragedy (or upset because you and the other adults around them are upset), you might want to check out the National Child Traumatic Stress Network . I wish more media outlets would read Child Sensitive Media Coverage of Trauma and Tragedy: the pictures, including on the front page of our local paper, have been ugly. Our Education Librarian, June Cheng, has more resources on her School Counseling Research Guide.
Above all, we, as human beings, look for community during times of stress. Take advantage of any local resources, whether they be your friends and family, religious organizations, social clubs, or community gatherings to talk, grieve, and just be together.
I hope this helps someone; at least I feel like I'm "Doing Something".