World Crisis Online

Many residents are asking why they were not warned about the risks The mayor of La Paz, Luis Revilla, told the BBC that since Sunday the affected area had almost doubled in size, from 80 to 140 hectares, but he believed the worst was over.

He said he hoped the weather would not deteriorate.

Despite criticism from residents, who complain they had received little information of the dangers their houses were facing, Mr Revilla said the authorities were doing everything they could considering the scale of the disaster.

“This is the biggest landslide in the city of La Paz since records began,” he said.

“All the preventive measures we had put into place in the area proved insufficient to stop a landslide of such magnitude.”

One of many involved in the rescue effort in Irpavi II is Fabian Yaksic, a member of parliament.

He says that, among the misery faced by homeless residents, thousands of people living on lower ground face the prospect of being without water for six months or more.

“We carried out an inspection and found out that, unfortunately, the main pipe [which takes water to many parts of the southern district of La Paz] is broken,” Mr Yaksic says.

“A new pipeline needs to be built,” he says.

But the pipes may have to be imported from as far away as the US, adding more time to the repair work.

Exposed city

The clear-up is set to take months Landslides are common in La Paz, and every year whole chunks of mountains crumble, and sometimes bury residents alive. Alain Malatrait, a French geologist who made a risk assessment of the city ground 30 years ago, told the BBC that 60% of it was prone to geological problems.

“The risks in La Paz are water erosion, gravitational movements [such as landslides], flooding by rivers and earthquakes,” he says.

“There are several places that are exposed to landslides but it is difficult to know which neighbourhoods are more at risk now, and which ones will be next.”

La Paz, a city of a million people, has grown rapidly, often at random, in the past few decades along the sides of its many canyons.

It also sits on an estimated 400 rivers and underground streams, which swell during the rainy months of January and February.

Given the known risks faced by the city, homeless residents are asking why permission was given for their houses to be built on steep slopes so vulnerable to landslides.