Damn shame. Very familiar with that area, family there goes back to early 1700’s and I went to school in the ‘Burg. We used to frequent the area up near the Branch for swimming, camping and just general driving around.
Confined spaces eat people up exactly like this, it’s a textbook case for hazmat Health and Safety.
Two subcontractors were “eaten” up at the giant Stickney wastewater treatment plant near Chicago recently H2S I believe. I would hazard a guess the usual attitudes a tough guy hold your breath no need for sissie procedures, after the fact its the God has abandoned us crying shtick of the primitive (and god loves lawyers it seems).