This small caption says the photographer was the official photographer of the building firm and - who would have thought it - the picture was somehow staged.
This is one of the pictures that really remained impressed in my mind when I saw it first, while a child.
Kind of funny. When I was in college (60's) had the good fortune of getting a job on a steel construction gang during summers. Great $$ and worked 30 stories up and never gave it a second thought to walk edge forms, no safety lines, etc. Now, you can't get me on the roof of the house. The picture gives me the willies!