Watch video of the failed attempt to close the leaking pipe.
From National Geographic:
"We don't have any idea how to stop this," expert says.
Last week the joint federal-industry task force charged with managing the spill tried unsuccessfully to lower a 93-ton containment dome (pictures) over one of three ruptures in the rig's downed pipe.
If the oil can't be stopped, the underground reservoir may continue bleeding until it's dry, Simmons suggested.
The most recent estimates are that the leaking wellhead has been spewing 5,000 barrels (210,000 gallons, or 795,000 liters) of oil a day.
And the oil is still flowing robustly, which suggests that the reserve "would take years to deplete," said David Rensink, incoming president of the American Association of Petroleum Geologists.
