At the 24th Nagano Iizuna Marathon on October 3rd, 33 runners, staff and spectators were stung by what appeared to be killer hornets. According to officials the injured people were all taken to hospital for treatment and none of the injures were serious. Despite this organizers stopped the race to ensure the safety of all those taking part.
We've all had races canceled due to inclement weather, but killer bees? What has been the strangest thing that has caused the cancellation of an event you've been involved in?