Blown-out oil well faces final pressure test

LESTER HOLT, anchor: Now to the Gulf of Mexico and the Louisiana coast, where residents are hoping they've heard the last from BP 's blown-out well. NBC News chief environmental affairs correspondent Anne Thompson has been following this story from the beginning. She joins us tonight from Houma , Louisiana . Anne :

ANNE THOMPSON reporting: Good evening, Lester . Late tonight the crew of the Development Driller III will perform a pressure test on the cement seal at the bottom of the Macondo well. It wants to see if that seal can withstand 1150 pounds of pressure per square inch for about a half hour. If it does, then it's up to national incident commander Thad Allen to declare this well dead once and for all. Before the final pressure tests could be conducted, workers had to bring up the drill pipe, coming out in 125-foot sections from the relief well. This is John Wright 's 41st relief well. But this spill and its impact, he says, make it the most important of his career.

Mr. JOHN WRIGHT: It's the fact that it had done so much damage. We were able to help solve and fix something that so many people wanted and needed fixed as quickly as possible.

THOMPSON: Almost five months ago the Macondo well exploded in fire, killing 11 men on the Deepwater Horizon rig and spewing nearly five million barrels of oil. BP amassed a small floating city at the site to contain an environmental disaster unlike any in the nation's history. Today just a handful of vessels remain, this chapter of the disaster now ending with the bottom kill. This is what they had to hit, a hole an inch smaller than this dinner plate, just eight inches wide, 3 1/2 miles below the surface of the gulf, and then fill it with cement. On the Development Driller III there is a sense of accomplishment. But for many of the gulf's fishermen, the anxiety remains. Donna and Junior Knockin are shrimpers.

Ms. DONNA KNOCKIN: They can kill all they want, but it's not going to do no good because the oil is already on the surface floor. The damage is done already.

THOMPSON: And that is why there will be no celebrating once the well is officially declared dead. It has simply taken too much, too many lives and

too many livelihoods. Lester: Anne Thompson in Louisiana tonight,

HOLT: