After two gunmen went on shooting rampages at two major universities, scientists at both institutes have been conducting extensive research about how students who witnessed the tragedy were affected by the event. They are developing new insights into conditions such as posttraumatic stress syndrome, and why some people develop it after witnessing violence and\/or coming close to being killed, and others seem to heal relatively quickly on their own. Researchers from the University of Montr\u00e9al have been studying survivors of a shooting rampage at Dawson College, also in Montr\u00e9al, that occurred in September of 2006. Lead researcher Natasha Dugal and her colleagues found that a significant percentage (about 6%) who survived the shooting developed a new drug or alcohol addiction within 18 months of the event. About 950 students were involved in the study, which found that 30% experienced psychological disorders after the event, most frequently posttraumatic stress syndrome, depression, and social phobia. Many told researchers that despite counseling, they still do not feel as if they have completely recovered from witnessing the shooting. One woman said that even six years later, "I'll be somewhere crowded and I just get this overwhelming feeling that someone has a gun and I have to leave right away. It's my new normal." The second shooting occurred at Northern Illinois University in De Kalb, Illinois, on February 14, 2008. Stephen Kazmierczak, 27, entered a lecture hall with guns hidden in a guitar case. After climbing on stage, he was able to fire more than 50 rounds using a shotgun and three handguns, killing six and wounding 21 people before committing suicide. Terrified students, many of them bleeding, ran from the hall while others tried to hide under their seats as Kazmierczak kept firing. Right before this shooting, psychology professors had interviewed 1000 undergraduate women about past trauma, and immediately after the shooting, they re-interviewed 691 of them, and took genetic samples on 204. They found that those who are closest to the shooting itself were most likely to develop posttraumatic stress syndrome, but just being in the lecture hall, hearing gunfire, and seeing the gunman were also associated with the syndrome. However, the breakthrough result of this study was that certain genes make you more susceptible to the syndrome, while other genes were protective. The worst campus rampage in American history occurred at Virginia Polytechnic Institute and State University in Blackswell, Virginia, when a student shot and killed 32 people and himself.