Deadliest twister in decades

Massive tornado breaks grim 60-year record

Joplin reels as the rising toll makes Sunday's twister the single deadliest since 1950.  

Experts warn of new threat 

Also: 

• Chaos, bravery at hospital
• Scenes of devastation
• Raw video of rescue

New threat brewing after killer tornado

As Joplin reels from the deadliest twister in decades, experts warn of a "serious situation" on the horizon.

Details