Alex Hansen, [email protected] Crack front propagation using the fiber bundle model Disentangling the dynamics of a crack moving along a weak plane is along–standing problem that has interested the statistical physics community for nearly twenty years. The advancing crack front has been shown experimentally to exhibit all the signatures of a idynamical critical phenomenon. The theoretical approach to this problem has been a top–down one where one uses LEFM as a starting point. We take here an opposite view and approach the problem bottom-up. By using the fiber bundle model, we are able to connect with the LEFM–based approach explaining a number of open question on the way.