Wow, glad no one was killed in this incident.
these two individuals working there were very lucky
it could have been much worse
I don't know why they didn't build it like a pole barn, at least the walls would not have tipped over so easily and cause the roof to come down like that. I guess OSHA and who ever is going to do the investigation will get to the cause.
it would appear that with it being a car dealership that most of the interior space of the building would be open area
without interior walls to keep the structure from 'racking' a modest wind could cause the large roof structure to over power the exterior walls leading to the unfortunate collapse
bracing should have been put in place until the entire structure was complete
temporarily bracing the exterior walls to add rigidity until all the exterior walls were completely finished