About three weeks ago we had a structure fire involving a fairly new house. It originally came in as a basement fire (reported by the owner who was still inside) but about six minutes later fire was visible from several miles away. When we arrived it was fully involved, and about three minutes later the first floor collapsed into the basement/garage area, bringing everything else down with it.
Story and pictures here: http://ontariofirewire.com/archives/255
I took the first photo when I arrived, about ten minutes after the tones dropped.
Cause of the fire appears to be a propane explosion which blew out all doors and windows. This may have led to the fire taking such a fast hold on the structure, but the lightweight construction had a lot to do with it.
Collapse occurred about ten minutes after first ignition. We were lucky. This is our second encounter with this type of construction within a year. We are working with code enforcement to identify and mark all houses in our district with lightweight materials.
Watch out, brothers and sisters.