Tens of thousands of Putnam residents are in darkness Thursday evening as the result of a massive power failure. The Putnam 9-1-1 Center dispatched the Mahopac Falls FD to a report of an explosion and fire at the NYSEG substation on Secor Road in Mahopac Falls around 9 p.m. Lights flickered several times before the country was plunged into darkness. Reports of no power have been received from Somers and Yorktown in northern Westchester through Mahopac, Mahopac Falls, Brewster, Southeast, Carmel, Lake Carmel, Kent, Patterson and Putnam Lake into Pawling and Holmes in Dutchess County. Emergency equipment has been summoned countywide for reports of alarms sounding, individuals on oxygen needing assistance and burning odors. Calls to NYSEG seeking the cause of the outage were not returned.