The fatal explosion on the Deepwater Horizon rig in the Gulf of Mexico is a disaster...Oil exploration and production is intrinsically a hazardous business...While BP is not alone in suffering serious incidents, its recent past casts a shadow...The explosion at its Texas City refinery in 2005...[and the Prudhoe Bay oil spill in 2006] reverberate each time BP is linked with an incident...In the present instance, this is somewhat unfair. BP’s general safety performance has continued to improve under Tony Hayward, who became chief executive in 2007...[T]hough the rig was operating on BP’s behalf, the UK company was not responsible for it in the way it would have been for one of its own refineries.