TITLE: GCN CIRCULAR NUMBER: 29698 SUBJECT: Fermi GBM trigger 637977270/210320996 is not a GRB DATE: 21/03/23 18:34:26 GMT FROM: Suraj Poolakkil at UAH S. Poolakkil (UAH) reports on behalf of the Fermi GBM Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 637977270/210320996 at 23:54:25.07 UT on 20 March 2021, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to distant particles."