The weekend bombing of a Palm Springs, Calif., fertility clinic has cast a fresh spotlight on a 19th century philosophy linked to Russian revolutionaries. What does "nihilism" mean?

Investigators have identified Guy Edward Bartkus, 25, as the primary suspect in the explosion that injured four others.

After the brutal attack on Israel by Hamas militants, Israel has begun air strikes on Gaza. The World Health Organization warns that the health system there is at a breaking point.

No one immediately claimed responsibility for Sunday's bombing, which killed dozens and wounded nearly 200 people.

A rural Georgia monument that some people have dubbed "America's Stonehenge" has been demolished after a bomb destroyed one of its four granite panels. The bombing comes weeks after a Republican candidate for governor claimed the Georgia Guidestones were satanic and called for their demolition.

A day after the early Christmas explosion injured three people and damaged dozens of buildings in downtown Nashville, Tenn., large swaths of the state's communications networks were still down.