We have reporters working every angle of this sad, complicated story. We'll have the latest details about the killer, Seung-Hui Cho. We're following all fronts of the police investigation and looking at how the Virginia Tech community, and the nation, are coming to grips with this awful series of events.
On the anniversary of the Columbine school massacre, it is a day of complex mourning. Vigils and moments of silence across the country remembered the lives of the 32 victims of Monday's tragedy at Virginia Tech, reports Sharyn Alfonsi.
But the observances were haunted by ghosts of what the similar tragedy eight years ago at Columbine high School in Littleton, Colorado. Bill Whitaker will share the story of those close to the Columbine tragedy.
And our chief investigative correspondent Armen Keteyian will continue coverage of how Seung-Hui Cho obtained his weapons.
For CBSNews.com's complete, detailed coverage of this important story, click here.