  Via Monte Carlo simulations we study pattern and aging during coarsening in
nonconserved nearest neighbor Ising model, following quenches from infinite to
zero temperature, in space dimension $d=3$. The decay of the order-parameter
autocorrelation function is observed to obey a power-law behavior in the long
time limit. However, the exponent of the power-law, estimated accurately via a
state-of-art method, violates a well-known lower bound. This surprising fact
has been discussed in connection with a quantitative picture of the structural
anomaly that the 3D Ising model exhibits during coarsening at zero temperature.
These results are compared with those for quenches to a temperature above that
of the roughening transition.
