The huge earthquake that has devastated Sichuan today has echoes of the world's most deadly tremor of the 20th century, which killed at least 250,000 people, most as they slept before dawn in the city of Tangshan, some 70 miles northeast of Beijing on July 28, 1976.

At a magnitude of 7.8 the ‘76 quake was enormous, causing widespread damage even in the Chinese capital, where dozens also died. That tremor triggered a furore of rumours that it was an omen of future disaster. Less than two months later Chairman Mao Zedong was dead.

Today’s disaster near the town of Wenchuan in China’s southwest today also measured 7.8 in magnitude.

Many of those who died in Tangshan in 1976 were living in single-storey shacks or simply built brick dormitories built by a government that was struggling to feed and clothe its population at the end of the Cultural Revolution and one that was not aware of the need for earthquake precautions. Residents of Wenchuan live in similar relatively simple homes.

Wenchuan is home to about 110,000 people – a rather small community by Chinese urban standards. The apartment blocks will not have been built with any idea of earthquake prevention. They will have been thrown up by local property developers eager to provide homes to urban residents with rising incomes and to government servants entitled to better housing.

It is possible that many of these buildings, along with simpler, single-storey homes in the outskirts, could have tumbled down within seconds.

China is no stranger to earthquakes, but a tremor of this magnitude is still rare.

The worst tremor in recorded history rocked northwestern China – what is now Shaanxi province – on January 23, 1556 with a magnitude estimated at around 8.0 The death toll was put at 830,000.

But much of China is vulnerable to quakes. The scenic mountain town of Lijiang in southwestern Yunnan province was virtually razed in February 1996 when an earthquake measuring 7.0 wrecked the ancient town of traditional wooden homes, killing 304 people and injuring more than 16,000.

In the same province in 1988, an earthquake of 7.6 magnitude rocked a remote corner, killing 730 people and destroying about 400,000 homes.

For months China tried to hide the extent of that 1976 tremor in Tangshan, refusing offers of international aid and insisting that it would rely on its own resources to bring relief to the injured and the orphaned.

That, at least, has changed. There has been no attempt to hide the scale of today's disaster, just understandable confusion about the casualties and damage. China's Premier, Wen Jiabao, was quick to jump on an aircraft to the disaster zone.

“Facing disaster, the most important thing is calm, confidence, courage and strong leadership,” he told a TV crew on board. “We will definitely overcome this major disaster.”

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