The 1974 Pattan earthquake occurred in the rugged and isolated Hunza, Hazara and Swat districts of northern Pakistan at 12:11 UTC on 28 December 1974.
The 6.2 surface-wave magnitude quake had a shallow focal depth of 22 km and was followed by numerous aftershocks.
The main road leading into the area was blocked for about 25 miles (40 km) by landslides and rockfalls, hampering relief efforts.
The government flew in emergency supplies by helicopter until the roads were reopened on 13 January.
The earthquake, which reached MMI V in Kabul, Afghanistan, affected some 1,000 square miles (2,600 km2) of the Indus Valley region.