Someone needs to tar those roofers then throw them off the roof... Thats how you kill people. The open return is just icing on the cake. Its a wonder they didn't die. Someone that I know from the parts houses is a nincompoop that shouldn't be doing his own jobs, he almost killed a married couple with a disconnected fireplace flue. They were both in the hospital for almost 2 weeks and likely have permanent damage. That wasn't nearly as dangerous as what I see in those pictures...
America; first we fight for our freedom,
then we make laws to take it away.
-Alfred E Newman