Oil rig explosion

NEW ORLEANS, April 23 (UPI) -- Emergency teams in the Gulf of Mexico worked to keep the amount of oil leaking from a sunken drilling rig to a minimum.

The rig Deepwater Horizon sank Thursday, two days after an explosion on the platform about 50 miles off the coast of Louisiana. The rig was severely listing after the blast and apparently collapsed under the weight of water being dumped on it to control a fire.

Eleven workers are missing and rescue teams were expected to soon give up the search. It is feared many of the missing were assigned to jobs near the explosion point. While dozens of people were safely evacuated, 17 were taken ashore with serious injuries, with four listed in critical condition.

The concern of an oil leak was always present but officials said with the sinking that fear increased. It is believed oil is leaking from the well at a rate of about 8,000 barrels a day.

Emergency teams reported a sheen on the ocean surface at the rig site.

A robotic submarine is to be dispatched to the ocean floor to seal the well and halt the oil flow.

The company that operates the Deepwater Horizon said drilling activities may have hit an unexpected pocket of hydrocarbons, causing a pressure buildup that led to the explosion.