  We use the very simple and successful Cannonball Model (CB) of gamma ray
bursts (GRBs) and their afterglows (AGs) to analyze the observations of the
strongly extinct optical AG of GRB 010921 with ground-based telescopes at early
times, and with the HST at later time. We show that GRB 010921 was indeed
associated with a 1998bw-like supernova at the GRB's redshift.
