About 20 years ago,I was installing a 5 ton rooftop a/c and the crane fell. It was a 80 ton crane. He had his jib extention on and the crane hugging the building and turned 90 deg. Boom length fully extended was 130ft and he was all out trying to reach the roofcurb to set the unit on. I was between the unit and edge of the roof about halfway in signaling the operator.When it happened,I had my back to the crane watching the unit in the air....all of a sudden the unit started down fast...the crane engine revved like crazy,my helper shouted,and I went running. The building was a one story and had a 5 ft parapet wall,so it was 20 ft above ground.The crane was up on its side riggers and the bottom wheels were almost even with the roof and the boom arm all the way across the roof...laying on top of 5 air conditioners .Of course,it shook the whole building with ceiling tiles falling out,etc. About 200 people came running outside...to the side the crane was on. The operator panicked and started sucking his boom in.Well...about 25 ft shorter,the boom didnt have as much leverage and the crane fell back down...the 16" diameter steel ball came whipping across the roof (like a fishing reel) and whizzed by me ,missing me by 5 ft.(so my helper said,and I HEARD it ...bigtime). The crane barely kept from turning over the other direction (I'm still amazed it didnt)....and this with 200 people gathered around (mostly oilfield engineers at Petrofac LLC)...Talk about some peaved off people...whew! Anyways...to make a short story long

, there was a 3ft diameter concrete drainline pipe directly underneath the outrigger about 4 ft deep that the outrigger fell/busted into. I used to have pictures, but lost'em along time ago....actually,now that I think about it,I believe my employer at the time,got them to show his buddies. Needless to say,every since then, I am always very cautious around cranes (and I use'm several times a year). From that point forward,Petrofac insisted we use a 140 ton crane(guessing,its been along time ago...it had 3 turning tires up front on each side) with 175 ft boom (without jib,)...had to transport 100 miles round trip with city permits,etc.....very expensive.