Following reports in 1999 of a cluster of childhood cancers among students attending a school built on a former industrial site, epidemiological and environmental studies initially ruled out a possible link between these cancers and attendance at the school. In May 2001, reports of new cases triggered a crisis. A Scientific Committee (SC) comprising 16 experts was convened. The objective of this article is to analyze its work, the difficulties encountered—particularly in its relations with stakeholders—and the lessons learned. The SC’s tasks were to examine questions raised by the public, analyze the results of the investigations undertaken, and propose and monitor the necessary studies. Over three years, the SC carried out substantial work reviewing numerous epidemiological and environmental studies. The initial gap between social expectations and the proposed scientific approach, the lack of communication with stakeholders, and the shortage of resources constituted the main difficulties encountered by the SC. However, over time, a positive interaction developed between the SC and stakeholders, particularly the public. The SC recommends, in such situations, implementing coordinated, streamlined, and responsive expert review and decision-making mechanisms that integrate all stakeholders as early as possible. (R.A.)