It wasn’t just luck that led to the rescue of some victims pulled from the rubble a week and a half after the earthquake hit Haiti. They survived because of such factors as their general health, how they were positioned while trapped and the extent of their injuries, experts explain. For example, according to Paul Lyons, professor of family and community medicine at Temple University, people without significant trauma like severe head injuries and crush injuries were most likely to survive over the course of nearly two weeks: "Open wounds in a non-clean environment get infected, and this can turn into a system-wide infection that causes all your systems to shut down."