Last body count is 1100. Roughly the same as the General Slocum disaster in 1904. More details are coming out as well. Like the General Slocum, it's not a single cause, but a cascade of mistakes

1) A group of 300 pilgrims departed the bridge early without being cleared to do so. They proceeded east on street 204, and intersected a group of 5000 going south on street 223 toward the bridge. Street 223 terminates at street 204, and the pilgrims on 223 would have to have gone west on 204 to reach the bridge. Fences lining the road prevented escape into the surrounding tent city.

2) Scheduling on the Jamaraate Bridge is notoriously tight, and as such, not very tolerant of out of position groups.

3) Street 206, which is the next intersection north on street 223, was blocked off. 206, if open, would have provided a relief path from the group headed south on 223. Why 206 was closed is still under investigation. The Iranian and Saudi goverments, not real friendly at the best of times (differing sects of Islam), are offering different reasons.

4) It was 47C (~117 F) at the time, which may have contributed to the early departure at the bridge.

5) Concerns about training of the Saudis in regards to crowd control. Specifically, why they were unable to compensate for the rouge group of 300 before it covered the 600M distance between the bridge and the intersection.