Three of his students did a documentary for National History Day on the 1964 killing of three civil rights workers.

NPR: 'Mississippi Burning,' 41 Years Too Late

The Deepwater Horizon accident, in which an oil rig exploded killing 11 people, caused one of the worst oil spills in history.

BBC: BP faces temporary ban from new US contracts

For in Egypt, it was the moral force of nonviolence -- not terrorism, not mindless killing -- but nonviolence, moral force that bent the arc of history toward justice once more.

WHITEHOUSE: President Obama on a Historic Day in Egypt

President Calderon said the killing of Mr Moreno was the biggest blow the authorities had inflicted on the cartel in its history.

BBC: Sign supporting Nazario Moreno