Intercontinental earthquakes, such as the ones that rattled New Madrid, may not strike the same place twice.
NASA marked a trio of space tragedies with ceremonies on Thursday and Friday, commemorating the astronauts who lost their lives in accidents.
It's nine years since Columbia fell from the sky, ending the lives of Kalpana Chawla, Rick Husband, Laurel Clark, Ilan Ramon, David Brown, William McCool and Michael Anderson.
David Teeghman explains why he recently got a tattoo of the Three R's triangle.