Complex sentence: When Wendy panics, a fight breaks out between Kevin Fischer and Lewis Romero, and Lewis accidentally slaps Erin, causing Ian to get involved and they are both thrown off the ride, which crashes moments later as Wendy predicted.
Split into simpler sentences: When Wendy panics, a fight breaks out between Kevin Fischer and Lewis Romero. When Lewis accidentally slaps Erin, Ian gets involved and they are both thrown off the ride, which crashes moments later as Wendy predicted.