Unfortunately I don't have the resources here to draw lines on this picture, but I suggest people print it out and draw a few lines on it. You'll notice that most of the "round" holes actually have one or more segments of their circumference that are actually straight.
Consider the "PacMan" hole on the upper right. The leftmost edge seems to be fairly straight, and roughly parallel to the rightmost edge of the hole to its left, which is also kind of straight. I surmise that there is a roof beam right there, that acted as a fulcrum to the collaping roof material. Does anyone have blueprints of this building to check?
Then take a look at the four holes in a row that are just down and to the left of those holes. They all have straight edges, that are spaced very regularly. Again, it looks like the roof material collapsed around the support beams. Also, it's a bit hard to tell because of the angle the photo is at, but if draw a line parallel to the rightmost edge of the rightmost hole in the line of four, it matches almost perfectly with the leftmost edge of the hole at the top, which edge is again kinda-straight. If you draw a similar line for the left edge of the same hole, it matches the left edge of the hole just above it.
There are similar features for most of these holes, which indicates to me that the roof beams acted as "stops" for the collapsing roof materials, almost like using a ruler to rip a straight edge in a piece of paper, or breaking a tile on the edge of a workbench.
If anyone has photoediting software, perhaps they could paint a few lines to show these things.