Most of the 126 workers on the rig Deepwater Horizon escaped safely after the explosion about 10pm Tuesday (local time), the Coast Guard said. Three were critically injured.
The rig, more than 80km southeast of Venice on Louisiana's tip, was still burning today. It was tilting about 10 degrees. There was no estimate of when the flames might be out.
Helicopters and boats searched the Gulf of Mexico for any sign of the workers who had not been accounted for.
"We're hoping everyone's in a life raft," Coast Guard Senior Chief Petty Officer Mike O'Berry said.
The Coast Guard said there were 17 workers evacuated by air and sea but not all required hospital stays. Three were in critical condition, Rear Adm. Mary Landry said.
The other 98 workers were being brought in by boat and were expected ashore Wednesday evening.
When the explosion happened, the rig was drilling but was not in production, according to Greg Panagos, spokesman for its owner, Transocean Ltd. in Houston. The rig was under contract to BP PLC. BP spokesman Darren Beaudo said all BP personnel were safe but he didn't know how many BP workers had been on the rig.
Adrian Rose, vice president of Transocean, said crews were doing routine work before the explosion and there were no signs of trouble.
Coast Guard environmental teams were on standby to assess any environmental damage once the fire was out.
Since 2001, there have been 69 offshore deaths, 1,349 injuries and 858 fires and explosions in the Gulf, according to the agency, which did not break down the cause of the deaths, the severity of the injuries, or the size of the fires and explosions.
