Who is to Blame?

I think that all the people that were working for BP at the time deserve the blame. It's not all for the CEO to make sure of. As soon as the crew found out that there was something not working 100%, they should have investigated the issue further. But the fault can go back even further, to the people who designed the drilling rig. They should have made sure that they built everything with care and high quality materials, so there would be no problem that would make the drilling rig sink or explode. Then, the people who tested it out have some part to play. When they were testing it out, they should have investigated further in to anything that could cause a problem, it should have been fixed. If they had found nothing that may not function perfectly, then that's a problem with the people who built and designed the drilling rig.