Published: Apr 27, 2010 7:49 PM EDT

NEW ORLEANS, Louisiana  - BP says crews will begin drilling later this week to try and take the pressure off of a blown-out well spewing 42,000 gallons of crude oil a day into the Gulf of Mexico.

BP was leasing the Deepwater Horizon, the offshore oil rig that exploded last week, triggering the spill. Company spokesman Robert Wine said it will take up to three months to drill a relief well from another rig recently brought to the site where the Deepwater Horizon sank after the blast.

Most of the 126 workers on board escaped; 11 are missing and presumed dead. No cause has been determined. If the well cannot be closed, almost 100,000 barrels of oil could spill into the Gulf before the relief well is operating. That's 4.2 million gallons.

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