Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. BP Admits 'Fundamental Mistake' VOA News 26 May 2010 Oil plume is seen on the BP.com website, 26 May 2010 Photo: AP Oil plume is seen on the BP.com website, 26 May 2010 Energy giant BP is planning a risky maneuver it hopes will stop the gushing flow of oil into the Gulf of Mexico from a leaking offshore well. BP said it hoped to begin so-called "top kill" operation Wednesday, if preliminary tests showed it could be safe. The maneuver involves pumping heavy drilling fluid into the oil well to stop the flow of oil and gas.  Company officials have put the chances of success at 60 to 70 percent, because the well is located 1,500 meters beneath the surface and the "top kill" operation has never been attempted before at such a depth.  Late Tuesday, two U.S. congressmen released a memo saying BP had admitted it may have made a "fundamental mistake" in the hours leading up to the oil rig explosion that killed 11 crew members and started the leak. The memo says BP admitted it had continued work at the offshore oil well on April 20, despite receiving worrisome warning signals. BP says it will provide video of the "top kill" procedure. Earlier, it had been reported that the company might shut off the video link of the oil spill. Meanwhile, a senior U.S. administration official says President Barack Obama will travel to the Louisiana Gulf Coast on Friday to review efforts to counter the disastrous spill.  The Obama administration has come under pressure as oil washes up in the delicate Louisiana wetlands and other areas, endangering wildlife and livelihoods in commercial fishing and tourism. The administration has deflected calls to take charge of the operation, saying it is BP's legal responsibility to cap the leak and contain the spreading spill. A memorial service took place Tuesday in Jackson, Mississippi for the 11 workers killed in the April 20 explosion. Some information for this report was provided by AP and Reuters. .