It was canceled fairly quickly, but it was so big that it caught a lot of attention, so here’s what emergency-radio traffic said about that big callout at Avalon/Bradford this past hour, in the Luna Park business district near the West Seattle Bridge: Someone reported that people were coughing inside a Metro bus because of some substance someone released – possibly mace or something like it. A “hazmat multiple casualty incident” response, with many units, ensued, but didn’t last long. Apparently the person who did it got off the bus, and the substance dissipated, and the bus continued on to 35th SW; no contamination was found. Seattle Police were reported to be looking for the person responsible.