How the shooting unfolded over Twitter

As shots rang out at Clackamas Town Center one year ago, the horrifying news spread rapidly in real time.

Hundreds at the mall that day pinged loved ones with text messages, folks posted photos on Instagram and Twitter. And here at KATU News, our staff scrambled to piece it together bit by bit over Twitter.

Here's how it unfolded based on our tweets on Dec. 11, 2012: