The worst-case scenario, however unlikely, is that a shock to the Campi Flegrei system would set off a chain reaction that ended in an earthquake or even a full-on volcanic eruption. Similar disasters have happened before: In 2006, a scientific drilling project on the Lusi volcano in Indonesia triggered an eruption that killed 13 people and displaced 30,000. Scientists on the project argue that the hole they're drilling is too small to be dangerous. But at press time, the project was on hold. As the mayor of Naples, Rosa Russo Iervolino, told Newsweek last fall, without a guarantee that the project is safe, "there will be no drilling in any part of the caldera."