The Grand Mosque is usually at its most crowded on Fridays, the Muslim weekly day of prayer. Many faithful would have been gathered there ahead of evening maghrib prayers, which occurred about an hour after the tragedy.
The governor of Mecca region, Prince Khaled al-Faisal, has ordered an investigation into the incident and was heading to the mosque, the official @makkahregion page on Twitter said.
Here are some images of the horrific incident, that claimed over 100 lives:
Crane collapse at Mecca masjid kills 107 people
Crane collapse claims lives of over 100 people ahead of hajj on Friday at Mecca masjid.
Stormy weather causes crane collapse in Saudi Arabai
Massive construction crane crashed into Mecca's Grand Mosquestormy weather on Friday.
Mecca crane collapse: PM Modi, President condole loss of lives
PM Narendra Modi, President Pranab Mukherjee condole loss of lives in Mecca masjid crane collapse.
Ten Malaysians injured in Mecca crane collapse
Ten Malaysians injured and six missing in Mecca grand mosque crane collapse.
Mecca horror: Crane collapses at Grand mosque
Horror in Mecca: At least 107 people killed when a construction crane collapsed at the Grand Mosque.
107 pilgrims killed in Mecca Grand mosque
107 pilgrims including two Indians killed when a construction crane collapsed at Grand mosque in Mecca.
Horror in Mecca: Pilgrimage turned into tragedy
At least 107 people were killed when crane collapsed at Mecca Grand mosque.