it had hoped to start a static kill, pumping mud and cement from above into the blow-out preventers as early as sunday. today, the effort was postponed until possibly monday or tuesday because workers need to clean out debris they found in one of the relief wells being drilled. the debris is preventing a final section of pipe casing from being installed. that casing is essential for reinforcing the relief well and keeping it secure during the static kill. tom foreman has more for us tonight. tom? >> hey, randi. what they want to do is make sure that relief well is ready in case the static kill doesn't work. let's explain the static kill first. they'll pump fluid down into that blow-out preventer we've heard so much about. this is like that top kill they tried before, down into the line. this fluid is much heavier than the oil and, in theory, it will exert downward pressure on the oil and ultimately stop it. they can do this because with that cap on top, the oil is now at a more constant pressure