In this paper we deal with pedestrian modeling, aiming at simulating crowd behavior in normal and emergency scenarios, including highly congested mass events. We will present two models: the first one is an agent-based, continuous-in-space, discrete-in-time, nondifferential model, where pedestrians have finite size and are compressible to a certain extent. The model also takes into account the pushing behavior appearing at extremely high densities. The second one is a macroscopic (fluid dynamics) model characterized by the fact that the maximal density reachable by the crowd – usually a fixed model parameter – is instead a state variable. The model couples a conservation law, devised as usual for tracking the evolution of the crowd density, with a Burgers-like PDE with a nonlocal term describing the evolution of the maximal density. Interestingly, both models are able to reproduce the concave/concave fundamental diagram with a "double hump" (i.e. with a second peak) which shows up in the experimental literature when high-density crowds are observed.