Drooping ceiling fan blades

[Shawn Pottschmidt]

I scoped out an abandoned house today. There was a ceiling fan will all the blades drooping or hanging from the attachment site instead of being rigid. It looks like they melted. Anyone have an idea what this is from?

[Shawn Pottschmidt]

UPDATE: When I first went there the roof was covered in snow. It has since melted and lo and behold you can see where they had nailed down tarps to cover the roof. But the only thing left of the tarps was the pieces that were immediately nailed down to the roof. So anyone who mentioned moisture gets a prize.

Thanks everyone for responding.

case closed