  In light of the joint multimessenger detection of a binary neutron star
merger as the gamma-ray burst GRB 170817A and in gravitational waves as
GW170817, we reanalyze the Fermi Gamma-ray Burst Monitor data of one of the
closest short gamma-ray bursts: GRB 150101B. We find this burst is composed of
a short hard spike followed by a comparatively long soft tail. This apparent
two-component nature is phenomenologically similar to that of GRB 170817A.
While GRB 170817A was distinct from the previously known population of short
gamma-ray bursts in terms of its prompt intrinsic energetics, GRB 150101B is
not. Despite these differences, GRB 150101B can be modeled as a more on-axis
version of GRB 170817A. Identifying a similar signature in two of the closest
short gamma-ray bursts suggests the soft tail is common, but generally
undetectable in more distant events. If so, it will be possible to identify
nearby short gamma-ray bursts from the prompt gamma-ray emission alone, aiding
the search for kilonovae.
