Many of today’s critical infrastructures are organized in the form of a network, which are dependent on one another. A particular example is the power grid and the communication network used to control the grid. While this dependence is beneficial during normal operation, as it allows for more efficient operation, it can be harmful when the networks are under stress. Indeed, in such interdependent network infrastructures, a cascade of failures may occur where power failures can lead to communication failures, which, in turn, lead to cascading power failures.