The evolution of a heavy ion collision passes close to the O(4) critical point of QCD, where fluctuations of the order parameter are expected to be enhanced. We discuss both the appropriate stochastic hydrodynamic equations in mean field and via real time simulations near the pseudo-critical point. We find that the chiral fluctuations modify the transport coefficients of QCD, the production of soft pions is enhanced and the dynamical critical exponent is in line with theoretical prediction.