Final answer:
The flames in Omer's chest from 'Omer's Big Dive' symbolize a powerful emotional reaction. The exact cause is not specified in the provided excerpts, as they seem to be from various unrelated texts, not from the story in question.
Step-by-step explanation:
In the story 'Omer's Big Dive', the flames smoldering in Omer's chest are a metaphorical expression. They do not refer to a literal fire but symbolize a strong, often negative emotion that he is feeling internally. Such fiery imagery is often used in literature to convey intense feelings like anger, passion, or determination. The exact cause of these 'flames' within Omer would depend on the context provided by the story. Given that actual excerpts from 'Omer's Big Dive' are not provided, we can assume that the flames represent a significant emotional reaction to a situation or event in the narrative.