  We present an axisymmetric failed supernova simulation beyond black hole
formation, for the first time with numerical relativity and two-moment multi
energy neutrino transport. To ensure stable numerical evolution, we use an
excision method for neutrino radiation-hydrodynamics within the inner part of
black hole domain. We demonstrate that our excision method is capable to stably
evolve the radiation-hydrodynamics in dynamical black hole spacetime. As a
remarkable signature of the final moment of PNS, we find the emergence of high
energy neutrinos. Those high energy neutrinos are associated with the
proto-neutron star shock surface being swallowed by the central black hole and
could be a possible observable of failed supernovae.
