While pilgrims were traveling to perform the
Stoning of the Devil ritual, the stampede started when a pedestrian bridge railing was bent, causing seven people to fall off a bridge and onto people exiting the tunnel.
[3] The tunnel's capacity of 1,000 soon filled with up to 5,000 people.
[4] With outside temperatures of 44 °C / 112°F degrees, a failure of the tunnel's ventilation system was also blamed for many of the deaths.
[5] Some witnesses claimed they believed a demonstration was occuring, others reported that the power to the tunnel was cut.
[6] Saudi officials concluded that crowd hysteria occurring from the falling pilgrims was the cause.
[7]
Many who died were of Malaysian,
[8] Indonesian and Pakistani origin.