The Qayen earthquake was a major earthquake that struck Northern Iran's Khorasan Province on May 10, 1997. The largest in the area since 1990, it measured 7.3 on the moment magnitude scale and was centered approximately 270 kilometers (170 mi) south of Mashhad on the village of Ardekul. The third earthquake that year to cause severe damage, it devastated the Birjand–Qayen region, killing 1,567 and injuring over 2,300. The earthquake—which left 50,000 homeless and damaged or destroyed over 15,000 homes—was described as the deadliest of 1997 by the United States Geological Survey. Some 155 aftershocks caused further destruction and drove away survivors. The earthquake was later discovered to have been caused by a rupture along a fault that runs underneath the Iran–Afghanistan border. Damage was eventually estimated at $100 million, and many countries responded to the emergency with donations of blankets, tents, clothing, and food. Rescue teams were also dispatched to assist local volunteers in finding survivors trapped under the debris. The destruction around the earthquake's epicenter was, in places, almost total; this has been attributed to poor construction practices, and imparted momentum to a growing movement for changes in building codes. With 1 in 3,000 deaths in Iran attributable to earthquakes, one expert has suggested that a country-wide rebuilding program would be needed to address the ongoing public safety concerns.