  We present multicolor Hubble Space Telescope (HST) WFPC2 broadband
observations of the Type Ic SN 1994I obtained approximately 280 days after
maximum light. We measure the brightness of the SN and, relying on the detailed
spectroscopic database of SN 1994I, we transform the ground-based photometry
obtained at early times to the HST photometric system, deriving light curves
for the WFPC2 F439W, F555W, F675W, and F814W passbands that extend from 7 days
before to 280 days after maximum. We use the multicolor photometry to build a
quasi-bolometric light curve of SN 1994I, and compare it with similarly
constructed light curves of other supernovae. In doing so, we propose and test
a scaling in energy and time that allows for a more meaningful comparison of
the exponential tails of different events.
  Through comparison with models, we find that the late-time light curve of SN
1994I is consistent with that of spherically symmetric ejecta in homologous
expansion, for which the ability to trap the Gamma-rays produced by the
radioactive decay of 56Co diminishes roughly as the inverse of time squared. We
also find that by the time of the HST photometry, the light curve was
significantly energized by the annihilation of positrons.
