摘要:In Iran, Road Traffic Injuries (RTIs) with mass casualties occur repeatedly. Since Road Traffic Accidents (RTAs) occur far from health facilities, EMSs play an important role in reducing the disability and mortality resulting from RTIs. Thus, the study aimed to report Iraqi pilgrims’ bus which rolled over in the Malayer town. A mass casualty event occurred on 7 September 2017 when a bus full of Iraqi pilgrims rolled over on a road 4-km outside of Malayer, Iran. A large team of responders were dispatched including 5 ambulances with 10 EMTs along with 6 police officers serving in the area. The accident resulted in 35 injured patients (21 female and 14 male) as well as 11 deaths ranging in age from 2 to 65 years. Twenty-one of the injured were transported to the hospital and 14 patients refused transport and 12 patients sustained multiple trauma. The case has been described four phases of dispatch, on-scene, hospital and post-mission. Frequent calls made by laypeople were considered as the main challenge of dispatch phase. The response on scene was hampered by large numbers of lay bystanders. The over-crowding around the emergency units disrupted the medical care procedures in hospital phase. This case highlights over-crowding and laypeople interference at the scene disrupts the relief and rescue. To solve these challenges, the public education and police monitoring and control is recommended. Establishing a unified command post at the scene can facilitate effective coordination among relief and rescue organizations.