The Kingdom’s General Directorate of Civil Defense blamed the accident on severe storms, according to its official Twitter.
The governor of the Makkah region, the capital of which is Mecca, Khalid al-Faisal has ordered the launch of an investigation into the causes of the accident.
The tragedy comes ahead of the annual Hajj pilgrimage which is due later this month. Millions of Muslims from around the world will converge on the holy city between September 21-26.
Photos taken from the scene and posted on social media show bodies lying in blood on the mosque’s floor surrounded by construction rubble and metal parts of the crane.
The project to expand the mosque was launched in 2011 by late King Abdullah bin Abdulaziz. Earlier in 2015, King Salman bin Abdulaziz added five construction projects as part of the mosque’s expansion aiming to accommodate more than 1.6 million worshippers.
The projects cover 1.47 million square meters and include the construction of 78 new gates at ground level, according to the official Saudi Press Agency. The project and is being carried out by the Saudi Binladin Group at an estimated cost of US$26.6 billion, according to local press.
The Grand Mosque, or Sacred Mosque, surrounds the Kaaba – the most sacred site in Islam. The cuboid structure made of granite located in the mosque’s center is often called the House of Allah.
The Kaaba is the place of the Hajj – the Islamic pilgrimage to Mecca, which is one of the five Pillars of Islam. It is mandatory of all Muslims physically and financially capable to carry out the journey at least once in a lifetime. The period of Hajj in Mecca is considered to be one of the largest gatherings of people in the world.
There have previously been fatal events during the Hajj period in Mecca, mostly due to the overflow of pilgrims at Islam’s holiest site. Among the latest was a stampede on the last day of the Hajj in 2006, which killed at least 346 people and injured at least 289 more. Other fatal incidents have been due to a bomb explosion, protests, fires, traffic incidents and diseases, including MERS.
Originally posted: 87 Dead After Crane Collapses At World’s Holiest Mosque In Mecca