Build-up below old lakebed

Thomas Bell in Kathmandu, TT: The earthquake which struck Kathmandu on Saturday had long been anticipated, and feared, by residents. Nevertheless, this conurbation of up to 3 million people was poorly prepared for the day that was bound to come.

When the earth started to shake shortly before noon, residents in my neighbourhood rushed out of their homes and crowded into the centre of the small public squares, as far from the buildings as they could be.

The trees swayed like in a storm, for almost a minute.

For the rest of the day, and especially in the hours immediately following the first quake, powerful aftershocks continued to raise panic. Many people were preparing to sleep outdoors at night.

Kathmandu has often been called the most vulnerable city in the world to earthquakes. This reflects the fact that despite a long history of major quakes, there had been none since 1934, meaning that great tectonic energy was presumed to be stored beneath the city. Standing on a pre-historic lakebed, the city's soils magnify the tremors.

In recent decades, Kathmandu has swelled with dense, poorly built, new residential areas. New storeys have been added to old houses. The old neighbourhoods and new alike are warrens of narrow roads and multi-storey buildings.

Kathmandu's infrastructure - whether water and electricity supplies, or landslide-prone road links to the outside world - is fragile and overstrained at the best of times.

The death toll is currently stated at many hundreds, and that is likely to rise. But, mercifully, relatively few of the modern concrete houses in which most people now live seem to have been destroyed. It is the older brick and timber structures that fared the worst, including many historic monuments which collapsed completely.

A great horror seems to have occurred at Dharahara, a 19th century tower in the city centre, which collapsed completely. On a Saturday, its viewing platform, standing higher even than the surrounding shopping malls, would have been crowded with visitors.

The full extent of the damage is not yet known. There may be appalling discoveries in store. The town of Bhaktapur, around 15km east of Kathmandu, appears to have suffered worse damage. The soils there are known to be less stable.

Towns across Nepal have suffered serious damage. The situation in rural areas near the epicentre must be much worse. It is already known that climbers on Mt Everest were hit by avalanches.

Relief efforts will be required over a huge area, much of it almost inaccessible. Roads, where they existed, have been destroyed. Without electricity and with telephone networks stretched beyond their limit, Kathmandu was in near-complete darkness on Saturday night.

And the full extent of the disaster was not yet known.