seams odd to me that the grooves in the roof panels are not running in a direction that would allow the water/snow to drain down off the roof. Looks as if the stuff would lock into the grooves running right to left instead of top to bottom.
I don't think the roof metal is running the wrong way. The purlings are running parallel to the side wall with the roof metal perpendicular to it. It appears to me that a splice in the rafter failed and the roof colapsed.
I don't even see any purlins? It looks like the sheet metal is supported directly by the rafters, which is why they had to run the sheet metal grooves horizontally (which is wrong). If they had the correct purlins in place running horizontally between the rafters, then they could have run the sheet metal vertically on top of the purlins. This allows the rain and snow to drain off as it should.
As others have said, there are several issues with the way that roof was built that contributed to the accident.
