Eleven people injured by an explosion at a Black Elk Energy oil and gas platform on Nov. 16 have been evacuated and two are missing, according to the US Coast Guard.

The two missing are possibly overboard, US Coast Guard Petty Officer 3rd Class Jonathan Lally told Hart Energy. As of noon Nov. 16, Lally said there are no confirmed fatalities.

“The fire is confirmed to be put out,” Lally said, adding there is a report of a petroleum sheen in the area. Officials with Black Elk, based in Houston, could not immediately be reached for comment.

By early afternoon, Black Hawk posted this on its website: “Our thoughts and prayers are with those who are impacted. We have Black Elk personnel on the scene and en route. We are still collecting information at this time.”

The platform, which has 22 personnel, is about 32 km (20 miles) southeast Grand Isle, La. It operates in 17 m (56 ft) of water. The explosion was reported to the Coast Guard at 9 a.m. CST.

The Coast Guard has two small boats, two helicopters, and a fixed-wing aircraft at the scene, Lally said. Additionally, two Coast Guard cutters are en route to the platform, Lally said.

The conditions of those injured are not immediately known, according to Lally. Six were taken to hospitals and three were treated by EMS. New Orleans-based WWL-TV reported that four people in critical condition were transported by helicopter.

Nine additional platform workers were evacuated to nearby rigs and platforms.

At this point, it is not clear what caused the explosion and fire. Coast Guard Capt. Peter Gautier told WWL-TV early reports indicated that maintenance workers were cutting into a pipe and that oil may have escaped, causing the explosion.

Lally said a joint investigation will be conducted by the Coast Guard and the US Department of Interior’s Bureau of Safety and Environmental Enforcement.

In June 2011, the privately held company acquired Gulf of Mexico assets for an undisclosed price, including 40 fields with 399 wells.

Just last month, Black Elk announced a 23-well capital campaign. The company said it planned to begin drilling and major rig work on the first of the 23 wells starting in November.

The explosion comes just one day after BP agreed to pay a record $4.5 billion in fines and pleaded guilty to 12 felony and two misdemeanor charges as well as indictments against two supervisors and a former BP executive in connection with the Deepwater Horizon accident. The accident, which happened offshore Louisiana in April 2010, claimed the lives of 11 people.

US Rep. Ed Markey, D-Mass., the top Democrat on the Natural Resources Committee, said the tragedy shows that safety for offshore drillers is not a “settled matter.” He expressed sympathy those affected by the explosion.

Markey said in a statement he will be asking Black Elk, the Interior Department, and the Coast Guard for full reports on the tragedy.

President Barack Obama has steps to increase safety standards for blowout preventers, well design and construction in offshore drilling, Markey added.

But, “Congress still needs to pass legislation that codifies the actions taken by the Obama administration, increases penalties and liabilities for companies that spill, and ensures that the agencies charged with overseeing offshore oil drilling have the resources they need to protect workers and the environment,” he said.

Contact the author, Darren Barbee, at dbarbee@hartenergy.com.