I think the school handled the situation properly. They could not have forseen a crazed gun man pulling off a second attack. I believe they thought the first shooting was just an isolated incident. From my understanding the campus is very much like a small town with 11,000 visitors and students milling about. Imagine shutting down a small town in only a 2 hour time frame, nearly impossible.
Second, I hope that the tragedy will inspire those on Capital Hill to push for legislation allowing access to mental health care for all Americans. Disorders which can but do not always lead to homicidal rage such as depression, bi-polar disorder, and schizophrenia are treatable. Do you know how many Americans suffer from these conditions but don't seek treatment because they don't have health insurance and cannot afford it? I imagine it's a lot. I bet if we as a nation had access to mental health care we would see a steady decline in violent crimes and even substance abuse.