Fire that put itself out.

How can a fire put itself out? My neice emptied her ashtrays into trashcan and left house for 5 hr. When she returned the wicker trash can had burned up and bout a foot all around it also which was carpet. The fire had somehow put itself out. Does anyone know how?

It ran out of burnable material?

a fire has to have oxygen to burn. With the carpet burning only a little bit around the trash can, my guess is that no windows/doors were open, and the heating/ac unit was not running at the time it was burning. Other wise the carpet would have continued to burn.

I believe thrd28392 is correct in his theory that the fire did not have oxygen to burn.