It was the latest of several recent earthquakes to affect Padang
Padang is one of Indonesia's major cities, the bustling capital of West Sumatra province.
A relatively prosperous port city with a population of about 900,000, it lies on a coastal plain backed by mountains.
It is a home to the Minangkabau ethnic group, whose traders spread its traditions - including their famed spicy food - as they settled across the country.
The city also lies on one of the world's most active fault lines, making it vulnerable to the earthquakes and tsunamis that have become an increasing concern to residents in recent years.
Strong earthquakes with epicentres near Padang killed dozens of people in March 2007, and the city was considered to have become more vulnerable after the tsunami that devastated Aceh province in northern Sumatra in 2004.
"Everything changed after the Aceh tsunami - people were kind of living in fear," said Bruce Emond, an editor on the Jakarta Post newspaper who has lived in Padang and visits regularly.
"We've been waiting for a big quake," he said. "The wealthy areas are right next to the sea so a lot of people have been very concerned that these wealthier areas of the city would be hit - the commercial enclave."
"I'm sure there were many who had an escape plan ready."
He said that once Wednesday's earthquake struck, many people immediately started fleeing for the mountains in fear of a tsunami.
Padang is important to Indonesia but it is often a point of transit for travellers.
PADANG: KEY FACTS
Population of 900,000, capital of West Sumatra province
On coastal plain, surrounded by mountains inland
Lies on one of world's most active fault lines
Near major quake epicentres in March 2007 and April 2005
They leave to go surfing or trekking on the Batu and Mentawai islands, or head to the hill town of Bukittinggi or to Kerinci Seblat National Park.
The climate is hot, humid, and very wet, with the area receiving an average of more than 4,300mm (170in) of rain each year.
Culturally, it is known for the unusual matrilineal system of the Minangkabau, whereby inheritance passes from mother to daughter.
Padang women are seen as being particularly forthright and powerful.
The region also has strong literary and musical traditions, though it is Padang's spicy cuisine that has perhaps won most renown as the city's traders set up restaurants across Indonesia.
It typically consists of hot curries and other dishes served up in dozens of small bowls.
The area's most important businesses include textiles and rubber, and transport of rubber across the province was reported to have been affected by the latest earthquake.
"For a city of such importance to Indonesia to be hit so hard is really something," said Mr Emond.
But he also said a large network of migrants who have settled elsewhere in Indonesia could be helpful in efforts to rebuild after the earthquake.
"The money's there, and the connection to helping your people."