One year ago, the island nation of Haiti was shaken by a massive earthquake that collapsed most of its buildings and killed more than 200,000 people. Today, engineers and scientists are among those hoping to help prevent a similar catastrophe in the future by designing smarter, more earthquake-proof buildings.

NewsHour Science Correspondent Miles O'Brien talked to several seismologists, engineers and earthquake scientists to find out how they analyze earthquake risks and take preventative measures. One seismologist from Purdue University had been observing the fault line underneath Haiti for years and knew there would be an earthquake eventually - he just had no way of knowing when.

Because it's currently impossible to give warning for when earthquakes will occur, scientists focus more of their efforts on building structurally sound buildings that will protect the people inside when the ground starts to shake. That involves planning for the effect of "horizontal gravity" - the back and forth shaking effect that earthquakes have on buildings. Scientists say Haitians are rebuilding smartly so far, if slowly, reinforcing and planning buildings so they never have to live through a similar event again.

"So, this type of motion tells us how the building dances around an earthquake. So...a tall building tends to vibrate at some natural frequency, almost as if you were looking at a slow-motion picture of some sort of tuning fork that's vibrating at some pitch. And so, if you excite the building at the natural pitch of the building, the vibration just gets bigger and bigger." - Tom Heaton, California Institute of Technology

"We cannot predict earthquakes. We had no way of telling whether it was going to be today, tomorrow, in 10 years, in 100 years. So, we did not put a day on it. And it's not that we were afraid to put a date on it. It's that, as a scientist, we can't." - Eric Calais, seismologist, Purdue University

1. What happened in Haiti on Jan. 12, 2010?

2. Where is Haiti?

3. What is seismology?

4. What causes earthquakes?

1. Why do you think Haitians never retrofitted or fixed their buildings to withstand earthquakes even though they knew their country sat on a dangerous, active fault line?

2. Why do you think it might be difficult for Haitians to rebuild their country the "right way" with reinforcements to prevent building collapses? What could help them do so?

3. What are some parts of the U.S. that are especially susceptible to earthquakes? What makes those places better prepared to withstand major quakes than Haiti?

4. Shortly after Haiti's massive earthquake, the South American country of Chile experienced an earthquake of nearly the same magnitude that damaged far fewer buildings and killed far fewer people. Why do you think Haiti was so much more vulnerable than Chile to a major quake?