The BBC article said they lived on pier structures. A fire collapsed the pier and the contents of the house fell into the water. http://news.bbc.co.uk/local/cambridgeshire/hi/people_and_places/history/newsid_9168000/9168497.stm
Makes sense. Pier houses are a lot easier to defend than those on solid ground. Not so much fun with the mosquitos, though, and they do not provide much protection when the lake freezes over.
Dagnubbit. I was hoping it was aliens.