Mudslides are caused by a range of triggers including earthquakes, blasting operations, soil erosion as a result of over logging and heavy rain.

As an excess of water collects at the top of a slope, it puts pressure on unstable earth and rocks below. This collapses causing devastating damage to everything in its path - as earth and debris are propelled down at speeds of up to 77kmph (35mph).

People caught in the mudslide are buried under tonnes of mud and debris. Rocks and heavy vegetation are picked up and carried along, demolishing buildings, roads and power lines leaving survivors without homes, water and electricity. Rescue efforts are often hampered by the destruction of road and rail links and many people die from disease and starvation in the aftermath.

One of the worst natural catastrophes of the century happened in 1999 when a mudslide in La Guaira, Venezuela, killed an estimated 35,000 people.