  The next Milky Way supernova will be an epochal event in multi-messenger
astronomy, critical to tests of supernovae, neutrinos, and new physics.
Realizing this potential depends on having realistic simulations of core
collapse. We investigate the neutrino predictions of nearly all modern models
(1-, 2-, and 3-d) over the first $\simeq$1 s, making the first detailed
comparisons of these models to each other and to the SN 1987A neutrino data.
Even with different methods and inputs, the models generally agree with each
other. However, even considering the low neutrino counts, the models generally
disagree with data. What can cause this? We show that neither neutrino
oscillations nor different progenitor masses appear to be a sufficient
solution. We outline urgently needed work.
