[Closed] More than 300 killed in Saudi Hajj stampede

[url= http://www.aljazeera.com/news/2015/09/pilgrims-killed-hajj-stampede-mina-mecca-150924082302232.html ]Very sad news![/url]
How do people get killed in stampedes? Is it a case of being pushed over and then essentially trampled?

The safety history of Mina isn't great. Looks like the stampedes are an annual occurrence. Surely they can change the layout to deal with this?!