I recently was reminded of a time years ago when K and I were out for a walk and I disappeared down a manhole... And to add insult to injury he didn't miss me till he was about 3 houses away and ready to cross the road.   I dropped to my shoulders down the manhole and at the same time lost my voice.... I tried calling to him but no sound came out... by this time he was at the corner and I am watching him and waving my arms. eventually after what seemed like hours, he turned around looking for me and finally he looked down and saw me waving.. what felt like hours had passed was instead minutes.  When Keith got to me he could see that the concrete had broken and crumbled around the cover and as I walked across it the concrete cover spun over and pinned my legs. I was trapped mid stride... I wore those indentations for over a year on my legs, fortunately nothing was broken,  Still to this day I cannot walk over manhole covers....