47 floor, double-glazed window 380kg, crane cable burst

We craned the double-glazed window, the crane was mounted on a roof. The working load of the crane is 500kg,
weight of double-glazed window 380kg + 45kg suction cup. From our part, no mistakes were made, the crane was
additionally reinforced with loads, we checked and filled up the oil in the gearbox, while inspecting the cable
we did not find any damages. The steel-wire cable broke, and caused a lot of damage.
All are alive, no one has suffered.
At the moment the work is performing under the reconstruction of the destroyed parts of the facade of the building.
P.S. Workers suggested to lift the double-glazed window with ropes. Each of rope has a force at rupture
30kN using a system of z-rigs, but this would have been much longer, but much safer.
The initiative and instructions to work with a crane did not come from the workers. Therefore, workers will not be financially
restore the destruction, the whole burden of responsibility lay with the organizers of this event.