, NEW ORLEANS, Apr 22 – The US Coast Guard launched a frantic air and sea rescue operation for 11 oil workers missing in the Gulf of Mexico after an explosion rocked a rig off the Louisiana coast.
Three people remained critically injured after the blast ripped through the Deepwater Horizon semi-submersible platform around 10:00 pm Tuesday (0300 GMT Wednesday), sending balls of flame shooting into the night sky.
Fifteen people were airlifted by helicopter and taken to local hospitals, as rescuers scrambled to evacuate the rest of the 126 personnel from the rig, operated by Swiss-incorporated contractor Transocean, which has headquarters in Houston, Texas.
The platform, under contract to BP Exploration and Production, Inc., likely suffered a blowout while drilling through rock at BP\’s Macondo prospect, said Transocean vice president Adrian Rose.
"There\’s undoubtedly some pressure buildup in the marine riser, which comes from the seabed," he told reporters, ruling out a shallow gas pocket as the cause of the explosion.
"Hydrocarbons under pressure — gas or oil — got into the riser, came up the riser, expanded rapidly and exploded."
But he stressed that the cause of the accident was still under investigation and that "we have no facts to say that it\’s actually a blowout. This is an assumption that we are making."
A local official told The Times-Picayune newspaper that the 11 missing workers were found safe, but the Coast Guard denied the report. It had initially indicated that up to 12 people were believed missing.
"We have no idea where the 11 people unaccounted for are but we will continue to search," said Eighth Coast Guard District commander Rear Admiral Mary Landry.
The platform, located some 52 miles (84 kilometers) southeast of Venice on the Louisiana coast, was tilting between three and 10 degrees and still burning nearly a day after the blast.
While three other vessels tried to douse the flames and ferried shocked workers, some with minor injuries, to shore, the Coast Guard searched the waters for signs of life using six cutters, one airplane and four helicopters.
Workers jumped at least 75 to 100 feet (23 to 30 meters) into the water to escape the fire. Survivors were found on the rig and in the waters surrounding it, some of them clinging to life rafts.
The Coast Guard said it would conduct a joint investigation with the US Interior Department\’s Minerals Management Service and BP. Coast Guard environmental teams were on standby to assess the damage after all workers had been accounted for and the fire extinguished.
BP vice president for Gulf of Mexico exploration David Rainey said that pollution from the explosion, if any was "minor," although stressing the situation could change. He said BP had activated oil spill response plans.
The fire was burning off much of the oil spilled during the accident, officials said.
Landry said the fire was been fueled by oil leaking from the well head, and "as long as that crude is leaching, we\’re going to continue to see that fire."
"They\’ve got a remotely operated vehicle, subsurface vehicle that can work to secure that source, to plug that well head, if you will, and if it can plug the source, then we can mitigate the fire," she said in an interview with CNN.
Among the 126 workers aboard the rig at the time of the explosion, 79 were Transocean staff, six were BP personnel and the remainder were third party workers, Rose said.
According to Transocean, the Deepwater Horizon platform is 396 feet (121 meters) long and 256 feet wide. It can accommodate a crew of up to 130.
Built by Hyundai Heavy Industries in South Korea in 2001, the rig can drill up to 30,000 feet deep and operate "in harsh environments and water depths up to 8,000 feet," Transocean said.
The company said it had dispatched emergency and family response teams to help the US Coast Guard and BP care for traumatized workers and search for the missing.
Transocean is the world\’s largest offshore drilling contractor, with a fleet of 140 mobile offshore drilling units, in addition to three ultra-deepwater units under construction.