Covid-19Regional Covid-19 Four Total Cases of COVID-19 in Thunder Bay District By NetNewsLedger - July 2, 2021 914 Thunder Bay – COVID-19 Update – The Thunder Bay District Health Unit (TBDHU) reports one new COVID-19 case in residents in the TBDHU Region. The single case is from travel outside of the district. Current active cases in the region are now at 4.