When the massive 8.8 magnitude earthquake hit Chile on Feb. 27, it devastated villages, displaced millions of people and took the lives of hundreds more.
But amid the chaos, a classified and highly sensitive operation by Americans and Chileans was underway on the outskirts of Santiago, the Chilean capital, to secure weapons-grade nuclear material -- the kind terrorists are keen to get their hands on.
"Nightline" was in Chile for several days before the quake struck documenting the work of the National Nuclear Security Administration's Global Threat Reduction Initiative (GTRI) team.
"This operation is an effort to secure nuclear material that terrorists could acquire to make a nuclear device, as well as radiological material that they could acquire to make some kind of dirty bomb," said Andrew Bieniawski, the NNSA assistant deputy administrator who oversees collecting and securing vulnerable nuclear material from civilian facilities around the world.
In Chile, the team has come to pack up the highly-enriched uranium from two research reactors that no longer need it. The HEU will be shipped back to the U.S. where it will be stored in a secure, classified facility and converted to non-weapons grade material.
So-called "fresh" or unused highly enriched uranium is a terrorist's dream. Because it doesn't emit high levels of radiation, it's easy to pick up and run with. It only takes a small amount -- about the size of a grapefruit -- to make a nuclear weapon.
"When the material is no longer here, terrorists cannot acquire the material [and] the country is safer. That's the bottom line," said Bieniawski.
There is reason to worry. Nearly 40 countries around the world have highly-enriched uranium or plutonium -- ranging from multiple tons to a few kilograms. Total world stockpiles are enough to make more than 200,000 nuclear bombs.
Much of the material is not completely secure. According to the International Atomic Energy Agency, there were nearly 250 reported thefts of nuclear or radioactive material worldwide from June 2007 to June 2008.
Three years ago, armed men breached security at a nuclear reactor in South Africa, which contained enough material for 30 nuclear weapons.
And this past February, peace activists jumped a fence at a NATO air force base in Belgium where the U.S. reportedly stores an arsenal of nuclear bombs. They didn't get inside the bunker where the nukes were, but they did wander around the "highly secure" base for as long as an hour before being arrested.
The security breach was particularly troubling because al Qaeda terrorist Nizar Trabelsi was convicted in 2003 of plotting to drive a car bomb into the same base after meeting with Osama bin Laden.
"We are more than redoubling our efforts to secure this material, to make sure that any individual or any groups of individuals can't just jump a fence or two and get very close to this material," said Secretary of Energy Steven Chu, who is in charge of overseeing nuclear non-proliferation efforts.
Chu, who won the Nobel Prize for physics, said it's "a lot easier than it used to be" to make a nuclear weapon.