Washington - Company executives and top drill hands on the Deepwater Horizon drilling rig argued for hours about how to proceed before a BP official made the decision to remove heavy drilling fluid from the well and replace it with lighter weight seawater that was unable to prevent gas from surging to the surface and exploding.

One employee was so mad, the rig's chief mechanic Doug Brown testified, that he warned they'd be relying on the rig's blowout preventer if they proceeded the way BP wanted.

"He pretty much grumbled, 'Well, I guess that's what we have those pinchers for,' " Brown said of Jimmy Harrell, the top Transocean official on the rig. "Pinchers" was likely a reference to the shear rams in the blowout preventers, the final means of stopping an explosion.

Brown said in sworn testimony on Wednesday that the BP official stood up during the meeting and said, "This is how it's going to be."

It was the kind of power struggle that's common on all offshore rigs, but the fight on the Deepwater Horizon had deadly consequences, employees and experts testified Wednesday at a government inquiry in Louisiana.

Tuesday night, a House of Representatives committee released a memo outlining some of those decisions, saying that the crew of the Deepwater Horizon had a number of warning signs extending over five hours that conditions were worsening deep underwater before the oil rig exploded in the Gulf on April 20.

Their memo, based on a briefing by BP's own investigators, provided fresh information about the failures on the ill-fated rig. However, the oil company's own inquiry continues to skirt a central question that may emerge in the Louisiana hearings being conducted by the U.S. Coast Guard and the Minerals Management Service: Why were so many warnings ignored and why did BP move forward with removing the drilling mud?

In its briefing to congressional committees, BP said that crews noticed unusual pressure and fluid readings that should have alerted them not to remove heavy drilling lubricants known from the well — a move that apparently allowed a sudden upwelling of gas that led to the explosion and sinking of the rig about 50 miles from the Louisiana coast.

"That's something you learn at well-control school," said Carl Smith, a former U.S. Coast Guard captain and expert witness. "If you're circulating fluid, you need to monitor how much is going in and how much is coming out. If you got more fluid out than in, it's an indicator that something's going on."

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