Melbourne, Australia. A crane hoisting drywall lost the load at about 15 stories causing a near miss accident. The load narrowly missing striking a car as you can see in the picture. The article isn't clear about how the accident happened outside of the claim that the load must have "snapped".
Rigging failures due to improper rigging are not uncommon. New York had one that permanently disabled a architect late in 2007. Many others happen that we don't hear about. The US is finally getting testing on national rigging standards that will allow for standardized testing. It should be helpful in making sure that loads are more secure and this happens less often. Having a qualified rigger in charge of attaching a load is critical because often an operator can't see the load. I picked a load in the blind once using four way rigging with self closing hooks. The rigger on the ground could not get the hook in the picking eye. He chose to close the hook with the load resting on hinged portion of the clasp. The load was 180 feet in the air before I could see what he had done and my only recourse was to have everyone stop and clear out until the load was safe again.
Another instance was a guy using a chain for rigging put a lock in the chain instead of finding the right rigging. That was the jobsite foreman. A rigger in the blind with no education or supervision can endager the entire jobsite and the public.
Another point, you shouldn't be hoisting over the public. You really need to find another way and this is accident is a great example of why.
Make sure that you have someone educated rigging your loads. If you are in the states or Canada look into NCCCO certification. Unions, Crosby puts on good classes. Call your rigging supplier and I'm sure that they can point you in the right direction