NBCNews.com: US News

• Investigation continues into train collision
  
  
  
  
• White House on the defensive
  
  
  
  
• Fla. town waits for Powerball winner
  
  
  
  
• Obama gets personal addressing grads
  
  
  
  
• Return of the typewriter?
  
  
  
  
• ‘The typewriter is not dead’
  
  
  
  
• Millions in the path of severe weather
  
  
  
  
• Midwest under severe weather alert
  
  
  
  
• Video shows workers near top of Washington Monument
  
  
  
  
• Tornadoes tear through Kansas, Oklahoma
  People in two states were taking shelter amid wailing warning sirens Sunday as tornadoes were confirmed to have touched down in Kansas and Oklahoma as part of an extreme weather system plowing through the nation's midsection.The system, which stretched from North Texas to Minnesota, also heaved hail -- dime to softball sized -- as well as heavy rainfall. Residents in downtown Wichita, Kan., were t...