A crane crashed through the roof of the Grand Mosque in the Muslim holy city of Mecca today, Saudi Arabia officials announced. The death toll from the tragedy currently sits at 65, the BBC reports. Details are few, but the crane collapsed as Mecca prepares for the yearly Muslim Hajj pilgrimage later this month. As CNN reports, the Grand Mosque or Masjid al-Haram is one of Islam's most important mosques; it surrounds the religion's holiest site, the Kaaba shrine, the destination of worshipers during the annual pilgrimage. Construction to expand the mosque has been ongoing for some time. (More Saudi Arabia stories.)