Around 11:25 AM on October 17th, during the 1000 warriors procession in Nikko, a horse in the parade became agitated, couldn't be controlled and got into the audience. A 57-year-old lady from Fujioka city, in Gunma prefecture broke her left foot bone and was taken to the hospital. She was sitting down while watching the procession and because of her impaired mobility (she was disabled), she was unable to escape when the horse got into the audience. She was the only one injured in this accident, other audience members around her could get away from the horse.
The management at Toshogu (the shrine organizing the festival) said the number of spectators during the two-day event was about 35 thousand and this is the first such accident in many years. "We train our horses very well, however, the horse was excited due to the crowd around him (maybe somebody used a flash to take a photo?). We are very sorry for the accident and promise we'll do our best to prevent it from happening again", they said.
Here's the horse making goofy faces at the audience:
And here - showing what his thinks of this spectacle:
And here - being calmed by his handler:
Edited to add:
Incidentally, I remember the same horse being frustrated and agitated during the even bigger parade in May. He so wanted to bolt out of there. His handler had a hard time controlling him. I guess it was only a matter of time before the horse made a run for it.