Boston Marathon bombing coverage: What did the TV networks learn? Anything?

It may have taken a weekend to process, but April 19 does now appear to have been the most dramatic day for network television news since Katrina's destruction of New Orleans. It was a roaring blast of images, facts, speculation, gossip, dead-ends, loose ends, wild conjecture, ferocious street reporting, and, at moments, a wild throw-caution-to-the-wind melee that had news crews rushing to the source of gunshots only to find themselves down another blind alley - since Katrina, which was a much bigger and more complex story, by the way.

Then it was all over, just before 7, when Dzhokhar Tsarnaev was cornered.

But really, it was just beginning. A period of introspection for an industry that's not particularly good at the introspection game. Mistakes were made, big ones, but rather than concentrate on those -- been plenty of press on those already -- let's take a quick look at what did work, and how that might result in a calmer, saner, more fact-based approach to huge breaking news stories in the future.