The phrase "bar on fire" can be replaced with a variety of synonyms to add more depth and vividness to your writing. Some alternatives include "blazing bar," "inferno lounge," "smoldering pub," "scorching saloon," and "roaring tavern." Each of these phrases evokes a sense of heat, danger, and excitement, perfect for intensifying the atmosphere of a scene. Additionally, incorporating more descriptive language such as "flames licking at the wood-paneled walls" or "embers raining down from the ceiling" can enhance the imagery even further. Experiment with different synonyms and descriptors to find the perfect phrasing to make your writing come alive.