Two people are missing and four more are in hospital with burns after an explosion and fire ripped through an oil platform in the Gulf of Mexico.
A small amount of oil spilled from the rig when workers using a torch cut into a pipeline on the platform.
US Coast Guard Captain Ed Cubanski said the well was not producing at the time of the explosion and no oil was leaking.
The fire had since been extinguished, said Coast Guard spokesman Drake Foret. He said Coast Guard aircraft and boats were searching for two missing people. Nobody was believed to have been killed in the fire.
The platform is for oil production from an established well, unlike the Deepwater Horizon rig, which was drilling an exploratory well for oil giant BP in deep water when it blew up and triggered a massive oil spill in 2010.
That site is well to the east of Friday's incident.
Taslin Alfonzo, of West Jefferson Medical Centre in New Orleans, said four workers were airlifted to hospital in critical condition with second and third-degree burns over much of their bodies.
The production platform, owned by Black Elk Energy, is about 25 miles southeast of Grand Isle, Louisiana.
The Coast Guard said 26 people were aboard the platform at the time of the explosion. Capt Cubanski said the platform appeared to be structurally sound.
After the April 2010 explosion on the Deepwater Horizon, that rig burned for about 36 hours before suffering structural collapse and sinking to the Gulf floor.
The Black Elk platform is in 56 feet of water. Capt Cubanski said 28 gallons of oil were in the broken line.
A federal official in Washington said a team of environmental enforcement inspectors was flying by helicopter to the scene. They will scan for any evidence of oil spillage and investigate the cause of the explosion.
Black Elk is an independent oil and gas company headquartered in Houston, Texas. The company's website says it holds interests in properties in Texas and Louisiana waters, including 854 wells on 155 platforms.