( CNN ) -- Companies involved in the sinking of the offshore drilling rig Deepwater Horizon made `` some very major mistakes , '' Interior Secretary Ken Salazar said Thursday after meeting with executives from the oil company BP . Salazar would not elaborate , telling reporters in Houston , Texas , that the cause remains under investigation . But he said the failure of the rig 's blowout preventer -- a critical piece of equipment designed to shut off the flow of oil in an emergency -- was `` a huge malfunction '' that has left oil gushing into the Gulf of Mexico . `` The investigation will lead to conclusions about what exactly happened , but it did n't work the way it was supposed to work , '' Salazar said . `` And from my own preliminary observations , there were some very major mistakes that were made by the companies that were involved . But today is not really the day to deal with those issues . '' The Coast Guard and the Interior Department 's Minerals Management Service are leading the investigation into the loss of the drill rig , owned by BP contractor Transocean Ltd . The slick has been spreading across the northern Gulf of Mexico since late April , when the drilling rig Deepwater Horizon blew up and sank about 40 miles off the mouth of the Mississippi River . Eleven missing workers who were aboard the rig are presumed dead . BP owns the damaged well at the heart of the slick . Efforts to shut down the well have failed , leaving it spewing about 210,000 gallons ( 5,000 barrels ) of oil per day into the Gulf of Mexico . There was no immediate response to Salazar 's comments from BP , which has blamed Transocean . Salazar 's meeting with BP executives -- his second trip to Houston in less than a week -- comes as oil washed ashore on Louisiana 's barrier islands and drifted west past the mouth of the Mississippi River . Workers also prepared to lower a massive containment vessel over the Gulf of Mexico 's two-week-old undersea gusher . Have you been affected by the oil spill ? Share your story , images . A pinkish-orange foam mixture of seawater and crude oil streaked across large stretches of water in the northern Gulf and turned up in the on the shores of the Chandeleur Islands , off southeastern Louisiana . Trace amounts of sheen had been reported on the shores of southeastern Louisiana over the past week , but the landfall reported Thursday appeared to the `` first impacts '' of oil from the spill , Coast Guard Rear Adm. Mary Landry told reporters . Doug Suttles , chief operating officer for BP , said mild weather gave cleanup crews more time to attack the spill . More controlled burns were conducted Thursday , after BP and the Coast Guard used fire to destroy several thousand barrels of oil on the surface Wednesday , he said . But the spill was spreading westward and is projected to drift toward coastal parishes past the Mississippi River delta , spurring Louisiana to begin shifting preventive efforts to its southwestern coast , Gov . Bobby Jindal told reporters Thursday . `` That obviously opens up many more vulnerable areas along our coast , '' Jindal said . `` We 're going to do everything we can to keep this oil out . '' The National Oceanographic and Atmospheric Administration already has closed the area to fishing , restricting a multibillion-dollar industry in the region . Suttles said BP held a meeting with parish governments and state officials , who offered ideas for beating back the oily tide and leveled criticisms . `` What 's clear is this is their home , '' he said . `` And what 's also clear is they 're passionate about protecting their home . '' Under federal law , BP is responsible for capping the well and paying for the cleanup . The company shipped a four-story-high containment vessel to the site overnight and expected to lower it toward the seabed nearly a mile below the surface late Thursday , Suttles said . The hope is that the container will collect the leaking oil , which would be sucked up to a drill ship on the surface . If the operation is successful , BP plans to deploy a second , smaller dome to deal with a second leak in the ruptured pipe . But getting the large structure into position could take several days , and the technique has never been attempted at the depth of these leaks . `` If all goes according to plan by early next week we hope to make it operational , '' Suttles said . `` As we always do , though , we stress this has never been done before . We 'll likely encounter numerous challenges , but we 'll remain committed to make it work . '' BP has stopped the flow of oil from one of the three existing leak points from the sunken rig , but it was the smallest of the three leaks and did not affect the amount of crude pouring into the ocean . CNN 's David Mattingly contributed to this report .
Firms involved in rig 's sinking made `` very major mistakes , '' Ken Salazar says . Coast Guard scrambles to clean up first patch of oil known to reach shore . Score: 6 Officials hope dome will capture oil leaking 5,000 feet beneath Gulf of Mexico .