At least 87 people were killed after a crane crashed earlier today in Mecca's Grand Mosque with Saudi Arabia's Civil defense adding another 184 people were injured in the fatal accident which takes place just weeks before Islam's annual Hajj pilgrimage which takes place between September 21-26.

The video captures the moment of the crane collapse:

#Saudi Civil Defense in #Makkah Grand Mosque to inspect site of crane crash; 65 dead - http://t.co/Q9sXlwlQwM pic.twitter.com/J5Bc2C54aO — Khaleej Times (@khaleejtimes) September 11, 2015

According to Al Arabiya, the reason for the crane collapse were strong storms in the area, although there has been no official explanation yet.

Some point out pictures circulating on social networks showing a lightning strike hitting the area of the crane moments before the fatal collapse. Others point out the macabre coincidence that this tragedy takes place on the 14th anniversary of September 11.

As Reuters reports, the pilgrimage, one of the largest religious gatherings in the world, has been prone to disasters in the past, mainly from stampedes as pilgrims rushed to complete rituals and return home. Hundreds of pilgrims died in such a stampede in 2006.

Ironically, today's disaster comes as Saudi authorities have since lavished vast sums to expand the main hajj sites and improve Mecca's transportation system, in an effort to prevent more disasters.

Saudi authorities began a major expansion of the site last year to increase the area of the mosque by 400,000 square metres (4.3 million square feet), to allow it to accommodate up to 2.2 million people at once.

The crane that collapsed on Friday was one of a number dotted around the site as part of the construction project.