It actually took me a minute of looking at it to realize what was missing. I guess when you are so use to seeing it there all the time, when its not it takes a minute to realize it.
I see the duck tape is still attached, which was probably holding the vent in place. 
The upper portion was still in the attic, who knows where the rest went.
Is that a 2X3 wall. Looks like something I would see in one of the old US Steel houses around here. (Post WWII 800 sq ft 3 BR 1 Bath)
Peter,
that is one of the new ventless furnaces, don’t see any problem.
How many dead??
Did they partially decommission a gas furnace to strictly a heat pump? Just using the gas units blower fan?
Your getting sleepy,sleeeepy, sleeeeepy.your dead!