Two horses became spooked and bolted into the crowd.
Authorities say a woman was killed and three others were wounded in a drive-by shooting in Compton.
Police were unable to control an unruly crowd of roughly 2,000 people in Hollywood Wednesday night, Los Angeles Police Department Officer Karen Rayner said.
Police have been forced to turn away a huge, unruly crowd that showed up to register high school students for 400 free summer school slots.
A taxi driver plowed slowly through a crowd on a sidewalk in a popular restaurant and nightclub zone early Saturday, severing the leg of one woman and injuring more than two dozen other people, police said.