  Injecting a sufficiently large energy density into an isolated many-particle
system prepared in a state with long-range order will lead to the melting of
the order over time. Detailed information about this process can be derived
from the quantum mechanical probability distribution of the order parameter. We
study this process for the paradigmatic case of the spin-1/2 Heisenberg XXZ
chain. We determine the full quantum mechanical distribution function of the
staggered subsystem magnetization as a function of time after a quantum quench
from the classical N\'eel state. This provides a detailed picture of how the
N\'eel order melts and reveals the existence of an interesting regime at
intermediate times that is characterized by a very broad probability
distribution.
