BP is preparing to deploy a 98-ton containment "dome" to try and stem a tide of oil gushing into the Gulf of Mexico and avert an environmental catastrophe. The operation to place the giant structure over the largest of three oil leaks is unprecedented and, facing depths of almost a mile, remote-controlled submarines will have to guide it into place, hopefully by the weekend. AFPTV gained exclusive access to the dome as final preparations were put in place. Duration: 00:44