Investigation Underway over Deadly Hajj Stampede

King Salman of Saudi Arabia is promising a speedy investigation to figure out what led to a deadly stampede during the annual Hajj pilgrimage.
    
At least 700 people were killed and 800 others hurt during the incident.
    
Witnesses say the stampede began when pilgrims met at an intersection in the valley of Mina, a site that all pilgrims have to file through in a single day. 

"I saw people falling on the ground, other people trampling them. People were trampled, and the situation was out of control," Wael Abdullah a stampede survivor recalled.

The Saudi Interior Ministry said high temperatures and the fatigue of the pilgrims might also have been factors in Thursday's disaster.