According to the findings of the Liebherr crane experts sent to Saudi Arabia the LR 11350 was erected at the time of the accident with a boom length of approximately 190m, parked outside of the Grand Mosque and put out of operation. Previously it had sporadically been used for assembly works. In the late afternoon of 11 September 2015, during a strong thunderstorm and sandstorm with measured wind speeds of 80km/h (according to the CNN Weather Service) and 105km/h (wind recording of a Liebherr Tower Crane near the place of accident), heavy rain falls and a sudden drop in temperature by 20⁰C, the crawler crane was caught by the wind and tilted over the last support rollers of its crawler tracks.
The operating instructions of the LR 11350 and the associated "Wind Speed Charts" show that the crawler crane could not withstand such a high wind load and that the boom should have been lowered to the ground preventatively to avoid the tilting of the crawler crane.
In the meantime Liebherr has taken this very tragic accident in Mecca as reason to point out again to the operators of comparable Liebherr cranes worldwide the influences that wind has on cranes and to the unconditional compliance with the appropriate regulations mentioned in the operating instructions.