It has always been a perilous affair to go on the Hajj, or Muslim pilgrimage to the holy places at Mecca in western Arabia.
For centuries the main dangers were disease, thirst, wild animals and the bandits who stalked the faithful en route to and from the remote and hostile Hejaz region where Mecca is located.
The Hajj is a duty every able-bodied Muslim must perform if they can afford it and now, in the modern era of safe international travel, getting there and back is no worse than any other journey.
Instead, it is the vast numbers of pilgrims - often in a state of religious fervour - crammed into the narrow Hejazi valleys where the Hajj rituals take place that pose the danger.
However, with about two million pilgrims present, a hundred dead represents a one-in-20,000 risk, which is far safer than the odds which their forefathers would have faced.
Improvements
The Saudi Arabian authorities, ever keen to assert the legitimacy of the Saudi dynasty which only took control of the holy places in 1925, have spent billions of dollars improving the Hajj infrastructure.
In particular, the government of King Fahd, who adopted the title Custodian of the Two Holy Places 1983, has poured money into improvements - notably the recent erection of thousands of fire-proof tents at Mina where pilgrims camp out for one night of the Hajj.
This was in response to a disaster in 1997 when nearly 350 pilgrims were killed in a fire started by a gas cooker which swept through the tent city at Mina.
Police helicopters also now fly over the throng to identify any potential crushes at bottlenecks, although it is admitted that little can be done to control such a large number of people all intent on perform a particular ritual in the few hours designated for it.
Paradise guaranteed
The location of the symbolic Stoning of Satan ritual, which was the scene of the 2001 disaster, when 35 pilgrims were crushed to death, has also been the cause of previous problems.
Similar incidents took place in 1994 and 1998, killing 270 and 180 people respectively.
In the latter disaster, the unfortunate victims were trampled to death when panic erupted after some pilgrims fell from an overpass when a parapet gave way during the stoning ritual.
The worst single incident occurred in 1990, when by Islam's lunar calendar the Hajj fell at the height of the sweltering Saudi summer.
More than 1,400 pilgrims were killed during a stampede in an overcrowded pedestrian tunnel connecting Mecca with Mount Arafat.
The authorities said the ventilation system in the tunnel broke down.
Of course it must be stressed, as an encouragement for Muslims to face the perils of the Hajj - ancient and modern - it is the Islamic belief that anyone who dies in the performance of this duty is guaranteed immediate entry to Paradise.