Here is a graph showing the percentage increase in visits (using GA) for June 15, 2012 vs an average Friday in June.
The incident occurred just just after midnight. It hit Twitter about an hour after that. As you can see below, once the story hit the morning news things really picked up.
Our servers handled the load just fine. For an incident like this, we move to a stripped down version that runs on an HTML only server (no apps or scripting platforms).
Thank you for the information. It is helpful!