Fred Hicks weighed in on something similar, and I posted his response
here (check for the bolded line "On the subject of ongoing environmental damage:").
Ultimately, I would treat it in a variety of ways depending on the desired challenge.
What I recently became comfortable with was letting players attack items as if they were characters. In the Breaking Objects section, items generally have the same shifts of Armor as they have Stress Boxes, so any attack against an object is applied as if hitting a character with Armor.
After that... ummm... I'd use the Time Duration scale to add shifts to that attack, allowing the player to Take Out the object or section after a certain amount of time. You could also let the player build up Maneuvers, but that could get boring.