Mecca accident kills 107

The accident happened at 17:30 local time, about an hour before evening prayers. The area had seen heavy winds, with thunderstorms and a sandstorm picking up before the collapse. On the day of the accident Saudi spokesman Ahmed bin Mohammed Al-Mansouri said that the crane, "Had fallen due to strong sandstorm, winds and torrential rains."

Meteorological data from Mecca on the afternoon of the accident shows windspeeds rising to 22kph or 6m/s shortly before the accident, before settling back down to around 3.7kph later in the evening. Liebherr's load charts for the crane list safe operational windspeeds of 9m/s. However, the available data is only hourly, and doesn't detail potentially higher speed gusts, or account for the effects of sandstorms. Liebherr's guidance on the load charts refers users to the full operating instructions.

The crane was part of a huge project to expand the mosque, the focus of pilgrimage for the world's 1.5 billion Muslims. The number of visitors to the mosque during the traditional five-day hajj reached more than 2 million in 2014, and in some years has exceeded 3 million. The Saudi government has been working to expand facilities in the area of the mosque, and the mosque itself, in a $10.6bn project that will see the mosque expanded from 356,000m2 to 400,000 m2, room for 2.5 million worshippers.

The crane collapsed over the side of the building, into the central area around the Kaaba, the shrine at the heart of the sanctuary. Local reports say the damage done by the falling jib was broken by the raised Tawaf bridge circling the Kaaba, possibly reducing the number of casualties.

Prince Khalid Al-Faisal Al Saud, governor of Mecca, has formed a committee to investiage the accident. The BBC reports that Saudi ruler King Salman visited the area, and promised that, "We will investigate all the reasons [of the collapse] and afterwards declare the results to the citizens."

The manufacturer, Liebherr, made clear it would support the investigation. Spokesman Wolfgang Beringer said, "Liebherr is extremely saddened by this tragic accident and the fatalities and injuries, and expresses its deep sympathy to the families of the victims. We hope that all those injured will recover quickly. As the crane manufacturer Liebherr does everything in its power to help bring the accident investigation to a speedy and logical conclusion."

Saudi Binladin Group has not yet replied to a request for comment.