Hajj is one of the five pillars of Islam, and all Muslims who are financially and physically able must undertake it at least once in their lifetime.
During this year’s Hajj, which began on June 14, temperatures had soared up to 51.8°C or 125°F in Mecca.
And many of people who died had walked long distances in direct sunlight without adequate shelter, according to Saudi authorities.
That’s because the majority of them did not have permits to perform Hajj, according to Saudi authorities.
To take part in Hajj, people have to register for a permit and purchase a travel package on an official platform.
But due to the high price of packages – which can cost up to more than 10,000 US dollars per person – many people try to access the site illegally.
They may do this through booking through illegal tour operators and smugglers.
This means they aren’t able to travel in tour buses and don’t have arranged food, water and accommodation in the heat.
Many of the deceased were elderly or suffered from chronic illnesses, according to Saudi authorities.
This is actually not the first time so many people have died at Hajj.
In fact, in 2015, more than 2,000 were killed after a stampede broke out, making it the "deadliest Hajj disaster in history”.
But the increasingly high costs of the packages in recent years has worsened the situation, especially for people from countries like Egypt and Jordan, which are struggling with rising economic desperation.
The timing of the Hajj, which fell during the extremely hot Saudi summer this year, has also become a growing challenge due to global warming.