BBC: BP officials desperate to stem a huge oil spill in the Gulf of Mexico will try to place a smaller dome over the blown-out well, it is reported. The so-called top hat dome could be in place within 72 hours, chief executive Tony Hayward said. The latest bid to plug the gushing well comes after previous attempts to stem the flow failed. A growing slick from the BP-leased rig is threatening an environmental disaster along US coasts. ‘Unprecedented …