An oil platform in the Gulf of Mexico caught fire Thursday morning, forcing its 13 crew members overboard and sending waves of anxiety along a coast that has just begun to recover from the Deepwater Horizon disaster. By early evening, the workers had been rescued with no serious injuries reported and the fire had been put out. Coast Guard officials said no oil could be seen on the water near the platform, contradicting an earlier report. In another year, the mishap may not have garnered much attention and been seen as one of the scores of fires and explosions that occur on offshore platforms in the gulf every year. But coming so soon after the explosion on the Deepwater Horizon rig in April, which killed 11 workers and set off the largest marine oil spill in U.S. history, it took on much larger significance. Environmental groups quickly issued news releases, arguing that the fire proved the wisdom of the federal moratorium on deepwater offshore drilling (although the platform was not drilling, nor was it in deep water). Officials from Mariner Energy, which owns the well, will now take their turn answering to Congress, following in the well-worn footsteps of executives of BP and Transocean, which operated the Deepwater Horizon. The three ranking House Democrats in the energy field -- Henry A. Waxman of California, chairman of the Energy and Commerce Committee; Bart Stupak of Michigan, chairman of the Oversight and Investigations subcommittee; and Edward J. Markey of Massachusetts, chairman of the Energy and Environment subcommittee -- sent a letter Thursday to Scott D. Josey, chairman and chief executive of Mariner Energy, requesting a briefing by next Friday. Officials from Mariner, echoed by others in the industry, took pains to note the differences between this fire and the explosion that sank the Deepwater Horizon. 'There was no blowout, no explosion, no injuries, no spill,' said Patrick Cassidy, director of investor relations for Mariner Energy, an oil and gas company in Houston with 330 employees and about $1 billion in annual revenues. Mariner, which plans to merge with a subsidiary of Apache Corp., holds oil and gas interests around the Gulf Coast, as well as in Arkansas, New Mexico, North Dakota and Wyoming. But 85 percent of its production comes from offshore in the gulf. The platform that caught fire is about 14 years old and is in a section of the gulf known as Vermilion Block 380. The platform has four columns standing on the sea floor at a depth of 320 feet, and seven oil-producing wells are connected to it. Its production, averaging 9.2 million cubic feet of natural gas and 1,400 barrels of oil daily, is much less than that of platforms being built in far deeper waters of the gulf. The fire broke out just after sunrise in the living quarters, as the crew was painting and cleaning the platform, Cassidy said. He said the company was investigating the cause but did not yet have any answers. 'It doesn't appear to be related to the wells,' Cassidy said. 'And it doesn't appear that there was any release of oil.' He said automatic shut-off equipment on the platform sealed off the oil and gas wells before the fire occurred and the crew abandoned the platform. But he could not explain why the equipment was activated. At 9:19 a.m., the Coast Guard received a call from a nearby platform saying that the Mariner Energy platform was engulfed in flames, Capt. Peter Troedsson, the chief of staff for the Coast Guard's 8th District, said at an afternoon news conference. The 13 workers who had been aboard were spotted from a helicopter, huddled together and floating in protective suits about a mile from the platform. Gov. Bobby Jindal of Louisiana visited a hospital where the workers had been taken. In a statement, he said he spoke to two of them, who told him that one of workers could not get a life jacket because it was too close the fire. 'Some of the workers held one of the men up in the water, which is probably why one worker was thought to be injured when seen from far away,' Jindal said. An offshore supply vessel called the Crystal Clear, which was at a nearby oil platform, picked the crew members up and took them to the nearest platform. They were taken to land by helicopter later in the day. The Coast Guard sent seven helicopters and six vessels to the scene. Earlier in the day, a response vessel had reported an oil sheen one mile long and 100 feet wide. But Troedsson said that Coast Guard responders at the site could not see any sheen. Responders working for Mariner were studying the wells attached to the platform to see if there were any leaks, but for now they appeared to have been closed off, he said. 'The company monitors each of these wells. and their data showed there's no flow,' Troedsson said. Similar assurances were made after the explosion of the Deepwater Horizon -- in that case, they proved to be wrong. By midafternoon, Troedsson said, the fire aboard the platform had been put out. Federal records show that there have been at least four accidents at that well in the past decade. At least one of them led to a serious injury, and another led to a hospitalization. Mariner Energy itself has been forced to pay at least $85,000 in civil penalties for safety violations over the same period, including in two instances last year. The fire reinvigorated the debate about the federal moratorium on deepwater offshore drilling, which has been fiercely criticized by industry officials and residents of coastal states. The moratorium is scheduled to expire Nov. 30. But Michael R. Bromwich, director of the Interior Department's Bureau of Ocean Energy Management, Regulation and Enforcement, is reviewing safety policies and records of deepwater drilling companies to determine whether the suspension could be modified or lifted sooner. The three most recent drilling approvals for the Vermilion Block 380, the area where Thursday's fire occurred, were approved by federal regulators in 1999 and 2000, using categorical exclusions, according to federal mining records. Categorical exclusions are waivers that allow companies to proceed with drilling without having to undergo an in-depth environmental review. This is the same type of waiver that was granted for the BP Deepwater Horizon project. Since the explosion on that rig, the use of categorical exclusions has come under attack as a prime example of lax regulatory oversight of the oil and gas industry. In August, a presidential commission decided that the use of categorical exclusions would be halted for deepwater drilling but would continue to be allowed for shallow-water operations. Jacqueline Savitz, a senior scientist at the environmental advocacy group Oceana, said the accident showed that the government needs to keep the moratorium in place for new offshore drilling to ensure the safety of rig workers and marine ecosystems. 'It's another reminder that drilling accidents happen all too frequently,' she said. But industry officials said the fire had nothing to do with the issues being addressed in the moratorium. The Shallow Water Energy Security Coalition, an industry group of several gulf operators, pointed out that there are many differences -- in equipment and relative risks -- between shallow-water production platforms and deepwater drillers. 'It is so unrelated to anything involved in the moratorium,' said Lee Hunt, chief executive of the International Association of Drilling Contractors. 'These platforms are regulated under a whole different set of standards.' 