Ten years ago, the city of San Diego, California, was surrounded on three sides by fire. The canyons were impassable, the freeways were closed, and the refuges were filling up. Local reporters and residents, as well as concerned onlookers from around the world, turned to the nascent social network Twitter to share updates using the #sandiegofire hashtag. Few knew what hashtags were at the time, but almost everyone instantly understood them. After that, well, hashtags creeped into everything, from citizen journalism and discussions at conferences to advertising and politics. But 10 years ago, it was the best way to collate many voices into one.

This special episode takes us back to that day in October of 2007 to the first use of the hashtag in a breaking news event. Players in the oral history are Michael Calore, Chris Messina, Leng Caloh, Joe Spurr, Nate Ritter, and Blaine Cook.

Some notes: Most everyone was in different locations for this show, so the audio isn’t studio-quality as usual. But we did our best. Michael’s original article about #sandiegofire from October 23, 2007. Visit KPBS online. This group of guests shared a lot of links before and after recording, so here’s some extra reading around the topics discussed in the episode. “When the Pendulum Swings Back,” by Tobias van Schneider. A couple of fun comments epitomizing the debate over adding metadata and markup to tweets. Linked hashtags on Twitter got support in 2009. The questions about readability continued. From the magazine: An oral history of the hashtag. Finally, Jimmy and JT weigh in.

Send the guests feedback on their personal Twitter feeds. Michael Calore is @snackfight. “Hashdaddy” Chris Messina is @chrismessina. Leng Caloh is @lengcaloh. Joe Spurr is @joespurr. Nate Ritter is @nateritter. Blaine Cook is @blaine. Special thanks to David Pierce (@pierce) who produced and edited this show. Tricky stuff! Bling the main hotline at @GadgetLab. Our theme song is by Solar Keys.

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