Archaeologists, scientists and even an orthodontist investigate remains believed to be those of a long-lost Egyptian Pharaoh.

Could a 20-cm piece of slate, uncovered by archeologists in 1983, be the final proof that the legendary King Arthur was not a myth, but a real king?

Each year, 6,000 Americans lose their lives on the job. Tens of thousands more are seriously injured or exposed to deadly poisons. Yet if the death is due to a company's willful disregard for federal safety regulations, the maximum penalty the employer faces is six months in prison.

See live coverage of the presidential primaries with Jim Lehrer, Mark Shields, David Brooks and Judy Woodruff.