US Gulf gas explosion injures six, one missing

A natural gas explosion injured six crew members of a pipeline maintenance vessel off the coast of Louisiana and left one person missing, the US Coast Guard said on Wednesday.

The explosion occurred late Tuesday while the Motor Vessel Jillian Morrison was clearing the gas from a shut section of a pipeline owned by ANR Pipeline Company into a tank towed behind the vessel, said Petty Officer James Harless, a Coast Guard spokesman.

The towed tank ruptured in the explosion, Harless said. Coast Guard investigators checked the pipeline and wellhead for damage at the location of the explosion 24km off the coast of Marsh Island, Louisiana.

ANR's parent company, TransCanada Corporation, said the blast did not affect its pipeline system or supplies of natural gas to customers.

El Paso Corporation's Tennessee natural gas pipeline, however, said the explosion led it to declare force majeure – meaning it cannot meet contractual supply obligations – on its pipeline south of Marsh Island.

The company said it expected the force majeure to continue for at least another day while it checks the pipeline for damage.

The search continues for a missing crew member, the Coast Guard's Harless said.

"We have no plans to end the search soon," he said.

Four injured crew members were flown on Tuesday night to a hospital in Lafayette, Louisiana, and two crew members were taken to a hospital in Houma, Louisiana, the Coast Guard said.

Three crew members have been released from the hospital after treatment, said John Deblieux, risk manager for the ship's owner Chet Morrison Contractors Inc of Houma, Louisiana on Wednesday.

The other three crewmen were listed in serious condition at the Lafayette hospital.

Initially, the Coast Guard said the ship was unaffected by the explosion, but Deblieux said the blast damaged the ship, which remained on the scene to help with the search.

The Coast Guard has not determined whether a problem in the towed tank or the pipeline triggered the explosion.

The Jillian Morrison's captain reported the explosion at about 8pm local time on Tuesday (1am GMT on Wednesday GMT), Deblieux said.

The Jillian Morrison is a 53 metre, four-point dive support vessel operated in the Gulf of Mexico by Chet Morrison Contractors, according to the company's Website. The vessel accommodates 34 persons, including the crew.