This area is subject to frequent seismic disturbances because the tectonic plate under the Indian plate hits the plate under Eurasia as it continues to move northward and to push the Himalayas ever higher. The region surrounding Quetta is highly prone to earthquakes. A severe quake in 1931 was followed by one of more destructive force in 1935. The small city of Quetta was almost completely destroyed, and the adjacent military cantonment was heavily damaged. At least 20,000 people were killed. Tremors continue in the vicinity of Quetta; the most recent major earthquake in which nearly 10,000 people died and earthquake occurred in October 2008 in which 30,000 people were killed. In January 1991 a severe earthquake destroyed entire villages in the Khyber-Pakhtunkhwa, but far fewer people were killed in the quake than died in 1935. A major earthquake centred in the Khyber-Pakhtunkhwa's Kohistan District in 1965 also caused heavy damage.