  The recent report of iron line features in the afterglow of the gamma-ray
burst (GRB) 991216 has important implications for the properties of the
radiating material and hence the nature of the immediate burst environment. We
argue that the putative strong Fe emission line can be attributed to the
reflected emission from Thomson-thick matter which is illuminated by a
power-law continuum. The ionization parameter of the material (i.e., the flux
to density ratio) is around 10^3, resulting in a Fe K line from He-like iron. A
supersolar abundance of iron is not required by the data. Interestingly, the
ionizing continuum must be harder than the observed one. We interpret this as
due to the fact that the observed continuum is dominated by the standard blast
wave emission, while the line is produced by reprocessing material located at
much smaller radii.
