Modeling and simulation of heterogeneous interconnected critical infrastructures and of their (inter)dependencies is essential to get a clear understanding of their behavior. Current solutions are generally dedicated to one sector and do not provide means for information exchange with other simulators. This paper tries to fill this gap by introducing a simulation environment overlaying existing simulators. The simulation environment we propose reuses existing simulators within various sectors (instead of defining a completely new environment) and coordinates the execution of simulators with timing constraints so as to represent the interconnected system in a simple and efficient way. We present the architecture of the simulation environment and the results obtained with a first version of its implementation. The results exhibit dependencies between the electrical and the GPRS networks.