(Houston, TX) -- Crews are battling a fire that's caused the partial collapse of a shallow-water drilling rig off the coast of Louisiana. Federal safety officials say beams supporting the derrick and rig floor have crumpled over the structure. No one was aboard when the platform caught fire early today. Hercules Offshore, which operates the rig, said all 44 workers were safely evacuated yesterday after the natural gas well ruptured. Firefighting vessels are on the scene. Preparations are also underway to drill a possible relief well.