I was going to look that up, too. I was visiting my folks in the ‘burbs west of Philly during college in the summer of ‘72 and remember the union violence well. Some things never change. Weren’t there lots of burnings of construction equipment the summer before, too, leading up to the riot?
I don’t remember specifically, but from the descriptions in the book, it sounds like quite a campaign, really a military campaign, by the construction workers; I thought it was interesting that the author of the book didn’t name “hizzoner” who seems to have orchestrated the invasion of the political dinner (maybe his name was in one of the photagraph captions, which don’t come up on internet), but it would have had to be Rizzo.