If you look at melting points of metals, aluminum (about 1100 degrees) is below that of wildfire (about 1300 degrees).  Adding alloys generally raises that temp. What is more telling are the houses reduced to ash.  Appliances, in particular, have steel chassis, as do other items found in a house (water heater, etc.).  Fireplaces are brick.  Brick and steel have melting points well about forest fire temps.  Where did they go in the photos?  How did the temperature exceed the melting point of steel (2500 degrees)?