No sir. The house was almost completely destroyed but I took him out safely before the muggles started to crowd around.
I'm assuming that 壊されっちまってた is simply colloquial for 壊されてしまっていた, but I'm puzzled by the です part. It was always my understanding that you could not add です onto a verb to make it polite. I would have expected to see 壊されてしまっていましたが.
What is implied by this use of です? Is it someone realising that they used the wrong verb ending to add politeness and then compensating by adding です? Is it a regional variation? Something else?
If it helps, the character speaking is Hagrid from Harry Potter. He uses pretty colloquial speech in the original book.