    Sentence 1: Before Sunday , 19 firefighters  assigned to wildfires had died on duty this year  » according to Tracey Powers of the National  Interagency Fire Center in Boise .    Sentence 2: Before yesterday , 19 firefighters  assigned to wildfires had died on duty this year  , Said Tracey Powers , spokeswoman for the  National Interagency Fire Penter in Boise .