  The emergence and evolution of real-world systems have been extensively
studied in the last few years. However, equally important phenomena are related
to the dynamics of systems' collapse, which has been less explored, especially
when they can be cast into interdependent systems. In this paper, we develop a
dynamical model that allows scrutinizing the collapse of systems composed of
two interdependent networks. Specifically, we explore the dynamics of the
system's collapse under two scenarios: in the first one, the condition for
failure should be satisfied for the focal node as well as for its corresponding
node in the other network; while in the second one, it is enough that failure
of one of the nodes occurs in either of the two networks. We report extensive
numerical simulations of the dynamics performed in different setups of
interdependent networks, and analyze how the system behavior depends on the
previous scenarios as well as on the topology of the interdependent system. Our
results can provide valuable insights into the crashing dynamics and
evolutionary properties of interdependent complex systems.
