The earthquake in Chile was many times stronger than the one in Haiti but it claimed 700 lives and not 220,000 as in Haiti
Clearly, Chile is a more prosperous country, with economic output per head of the population more than 10 times greater than Haiti. Haiti is the poorest nation in the Western Hemisphere, while Chile is the world's 46th richest. More pressingly, Chile is widely regarded as having the best-run economy in the whole of Latin America.
That has meant that buildings in general are better built, but Chile was also better prepared.
People in Chile knew the safest places to go to when the earthquake struck.
Also, since an even stronger earthquake in 1960, Chile has developed a seismic design code for new buildings, which has made them better able to stay standing in an earthquake.
One system that helps buildings stay up is called the "strong columns weak beams" system.
The idea is that buildings are held up by reinforced concrete columns, which are strengthened by a steel frame.
Concrete beams are reinforced with steel rods and joined onto the columns to make floors and the roof - this prevents pancaking.
If there is an earthquake, the idea is that the concrete on the beams should break near the end, which dissipates a lot of the energy of the earthquake, but that the steel reinforcement should survive and the columns should stay standing, which means the building will stay upright.
A mitigating factor in the Chilean quake was that its focus was 22 miles (35km) underground, off-shore and its epicentre was 70 miles (115km) from the nearest big city, Concepcion.
The energy from earthquakes falls the further away you are from the centre.
The Haitian quake on the other hand was only 8 miles (13km) underground and right on the edge of Port-au-Prince.