Amateur video captured the chilling moment a crane collapsed at the Grand Mosque in the Muslim holy city of Mecca. A loud bang can be heard followed by frantic movement among the crowds of worshippers at the site.
At least 107 people have died and 238 people were wounded, according to Saudi authorities. It comes days before the annual hajj pilgrimage which sees millions of Muslims converge on Mecca.
The civil defence authority said strong winds and heavy rains had caused the crane to topple over. Last year, Saudi Arabia began a major expansion of the holy site. As such the area of the Grand Mosque will be increased by 400,000 square metres in order to accomodate 2.2 million people at a time.
With such vast numbers visiting, Saudi authorities have invested heavily in improving safety and transport systems in order to prevent disasters.
A full investigation is now underway to assess the damage as well as the safety of the sites.
British Prime Minister David Cameron took to Twitter to express his condolences.