Ignorant Lazy roofers put mall workers at risk

What you see on the left is a set of deck nails which are used to secure the metal sheeting used on a flat roof to the roof beams .

But where I found these busted off ones is disturbing I was working in a mall in beaver county pa.
Installing a camera system and these came falling out of the suspended ceiling and it is a good thing I had my safety glasses on as I could have seriously had my eyes injured because of the negligence of the roofing contractor who worked on the roof and did not clean the ceiling and remove all the screws after what most likely was a re roofing job.
every tile I opened I found screws and I removed them as i found them or after the fell on the floor. Mall maintenance people where there while i was and observed the same problem while replacing water stained tile and where suppose to come and vacuum them all off the ceiling at some point .
this incident with these screws should never have happened if the roofer used good and proper techniques but as you can see the just did not care to.
I am sure the mall will not be using them any more either.