and missing in america. after seeing our report, one family s 30-year-old mystery finally solved announcer: this is nbc nightly news with lester holt good evening. the american west is scorching tonight under a smooth ring heat dome that won t giving producing temperatures never before seen in september. breaking records by as much as 5 degrees. sacramento no stranger to summer heat reaching a record high of 114 yesterday at 104, salt lake city topping its september record for the third time this month. and now a deadly emergency playing out in southern california where two people died in a fast moving labor day fire the region now a week into a dangerous heatwave the brutal conditions are also threatening california s power grid which remains on the brink of rolling blackouts to cope with demand miguel almaguer is in hemet, california, where firefighters are still battling that deadly and lightning fast wildfire. reporter: it exploded out of control so quickly, autho