  Due to the high energies and long distances involved, astrophysical
observations provide a unique opportunity to test possible signatures of
Lorentz Invariance Violation (LIV). Superluminal LIV enables the decay of
photons at high energy over relatively short distances, giving astrophysical
spectra which have a hard cutoff above this energy. The High Altitude Water
Cherenkov (HAWC) observatory is the most sensitive currently-operating
gamma-ray observatory in the world above 10 TeV. Together with the recent
development of an energy-reconstruction algorithm for HAWC using an artificial
neural network, HAWC can make detailed measurements of gamma-ray energies above
100 TeV. With these observations, HAWC can limit the LIV energy scale greater
than $10^{31}$ eV, over 800 times the Planck energy scale. This limit on LIV is
over 60 times more constraining than the best previous value for $\rm
E_{LIV}^{(1)}$.
