A large crawler crane has overturned onto the Grand Mosque – the Masjid al-Haram in Mecca, according to the Saudi Arabian Civil Defence Force.
The report now says that at least 100 worshippers have died, with a further 200 or more injured in the incident. Some of the fatalities and injuries were caused by subsequent panic and stampedes, rather than from a direct hit from the crane or falling masonary.
Original reports said that the crane was a tower crane - 20 Luffing jib cranes have been operating around the mosque since 2011 - but as more information came through and the death toll rose it became clear that the crane was a Liebherr LR11350 lattice crawler crane rigged with a long main boom, derrick mast and a long luffing jib.
The boom and jib were left at a high angle - almost vertical - facing into the wind, with little or no attempt to stow or lower the jib for the storm. The jib may well have triggered the overturn if the wind caught it and pushed it over the rear?
Local reports say that the crane was affected by exceptionally strong winds, with gusts significantly exceeding 65kph, coupled with a heavy sandstorm and a violent thunder storm.
The crane was not working at the time but caught the storm head on and went over backwards with the boom and jib masts piercing the mosque roof and sending heavy debris crashing onto those praying below, before the jib and its rigging came down on others.
This incident occurred as the authorities are preparing for the annual Hajj, with almost three million pilgrims expected to arrive in the coming weeks.
The boom was cut into sections and removed from the crane shortly after the investigation was completed. The full recovery then began in early October. A local official said that the crane will be scrapped, rathern than repaired and put back into service.