Last Thursday evening a young, troubled bicyclist from Glenview was hit and killed by a small pickup in the southbound lanes of Lake Shore Drive north of Belmont. The  Sun-Times and Tribune posted tentative and frequently revised first reports online, though those are now lost to us, and their ultimate news stories took up only a few lines. But the process by which an online community critiqued those first reports while inundating itself with rumors, conjecture, and first impressions was prodigious and awesome. I thank reader Patty Cronin for pointing me to it.

"To me," said Cronin in an e-mail Monday, "this was the Chicago journalism story of the last couple of days -- of big outlets moving fast, citizen journalists getting it wrong and right, the piecing together of the news of the bike rider who was killed on Lake Shore Drive on Thursday -- it was fascinating to watch the Trib and other outlets morph from one story to the final version, and to read the hundreds of comments from people who 'heard' what happened and weighed in. Ultimately, a couple of guys who were right behind the truck who hit the young man set everybody straight."

Here's a link to the first batch of responses at the Tribune's comments boards, and here's a link to the second -- hundreds in all. You'll see the original collective understanding of what happened -- the bicyclist was struck so hard by a hit-and-run cab on the Inner Drive that he flew over a barrier onto the Outer Drive, where he was hit by the truck -- suddenly give way to an account even more improbable, yet apparently true. According to a couple of self-identified eye witnesses who'd been driving right behind the truck, the victim had actually been trying to walk his bike across the drive (despite the extistence of a nearby underpass).

Beyond the hivelike energy devoted to getting at the truth, I was struck by a number of things, such as by how wildly inaccurate first reports can be and how unwilling most people with views to assert are to let shaky facts stop them, by how scornful people (granted, at a Tribune site) were of early Sun-Times reports that turned out be be about as accurate as anything else, by how determined so many people were to get to the bottom of what happened, and by how heartless and loutish some people will be when they can be heartless and loutish anonymously.

Is this how news will get put together in a world without reporters -- with relentless inefficiency?