In April of 2007 Seung-Hui Cho, a senior at Virginia Tech University, went on a rampage. By the time his murderous spree ended by suicide, Cho had killed 32 people and wounded 17 more. Most of those killed were shot as they sat in classes in the engineering school. Cho chained the doors shut to ensure it would be hard for his intended victims to escape. Panic broke out as students began to realize what was happening. When Cho came to one classroom, he found the door barred by the professor, 76 year old Liviu Librescu.