Indonesia - A powerful earthquake struck off the city of Padang on Indonesia's Sumatra island on Wednesday, killing at least 21 people and trapping thousands under rubble, an official said.

The quake caused widespread panic across the city of 900,000 people, and a hospital in Padang collapsed, said Rustam Pakaya, the head of the health ministry's disaster center in Jakarta.

At least 21 people had been killed and thousands of people are trapped in the rubble of buildings, Pakaya said.

TV footage showed devastation, with piles of rubble and smashed houses. Metro Television reported the roof of Padang airport had collapsed and other media said hotels were damaged.

The 7.6 magnitude quake was felt around the region, with some high-rise buildings in Singapore, 440 km (275 miles) to the northeast, evacuating staff. Office buildings also shook in the Malaysian capital, Kuala Lumpur.

The Pacific Tsunami Warning Center canceled an earlier tsunami alert.

Hundreds of houses have been damaged along the road. There are some fires, bridges are cut and there is extreme panic here, said a Reuters witness in the city, who also said broken water pipes had triggered flooding.

His mobile phone was then cut off and officials said power had been severed in the city. A resident called Adi later told Indonesia's Metro Television there was devastation around him.

For now I can't see dead bodies, just collapsed houses. Some half destroyed, others completely. People are standing around too scared to go back inside. They fear a tsunami, said Adi.

No help has arrived yet. I can see small children standing around carrying blankets. Some people are looking for relatives but all the lights have gone out completely.

Online news agency Detik.com said a hospital and a large market had also been damaged in the city.

Sumatra is home to some of the country's largest oil fields as well as its oldest and smallest liquefied natural gas terminal, although there were no immediate reports of damage to those facilities.

Padang, the capital of Indonesia's West Sumatra province, sits on one of the world's most active fault lines along the Ring of Fire where the Indo-Australia plate grinds against the Eurasia plate to create regular tremors and sometimes quakes.

A 9.15 magnitude quake, with its epicenter roughly 600 km (373 miles) northwest of Padang, caused the 2004 tsunami which killed 232,000 people in Indonesia's Aceh province, Thailand, Sri Lanka, India, and other countries across the Indian Ocean.

The depth of Wednesday's earthquake was 85 km (53 miles), the United States Geological Survey said. It revised down the magnitude of the quake from 7.9 to 7.6.

A series of tsunamis earlier on Wednesday smashed into the Pacific island nations of American and Western Samoa, and Tonga killing possibly more than 100 people, some washed out to sea, destroying villages and injuring hundreds.
LONG HELD FEARS

Geologists have long said Padang may one day be destroyed by a huge earthquake because of its location.

Padang sits right in front of the area with the greatest potential for an 8.9 magnitude earthquake, said Danny Hilman Natawidjaja, a geologist at the Indonesian Science Institute, in February.

The entire city could drown in a tsunami triggered by such a quake, he warned.

Several earthquake-prone parts of the country hold tsunami practice drills, and the national disaster service sends alerts via telephone text messages to subscribers.

But some experts have long said Indonesia needs to do more to reduce the risk of catastrophe.

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