Despite the peaceful nature of the Hajj and the great lengths the Saudi government has gone to to insure the safety of pilgrims during the Hajj, it has not been devoid of disasters. Due to the incredible number of pilgrims several calamities have befallen the city. During the Hajj in 1998 there was a stampede that killed 107 pilgrims. This was just the latest in a long number of casualties which included the deaths of 270 pilgrims in a tent fire in 1997, the deaths of 1,426 pilgrims in 1990 during a stampede, and the deaths of 402 people in 1987 after a group of Iranian protesters staged a anti-U.S. demonstration that brought security down around their ears. Measures the government have taken include, the use of fire-proof tents in all of the pilgrim tent cities to prevent uncontrolled fires, the basic expansion of all transportation routes widely used during the Hajj , the expansion of the Holy Mosque which now can comfortably accommodate 2 million worshipers simultaneously, and drastically increased security measures implemented by the Mutawwa'iin. While the Hajj is not completely safe, accidents like this are relatively limited and getting rarer and rarer with each coming year.