Columbia memorial

 

 Space Shuttle Columbia

Very bad news: Shuttle landing in question [CNN]
NASA Declares Space Shuttle Emergency [Washington Post]
Latest shuttle news from Google
Spaceflight Now updates: NASA says the shuttle was about 200,000 feet up and traveling at 12,500 miles per hour when contact was lost. From all the reports we're receiving, it is becoming clear that the shuttle broke apart over Texas.

update: Extensive coverage is being gathered at Jim Flowers' weblog and Scripting News, among others.