Who is to blame for the oil spill?

I feel that there are many parties or certain people that should be blamed for the oil spill. There are so many different aspects that go into the oil spill that I don’t feel one person should have the responsibility of such a horrible event on their shoulders. I think that the company that supposedly tested all the back up equipment in case of the cement failure should be at some fault. When the workers or whoever applied the back up it didn’t work and if they had know that they wouldn’t have used it. Also the workers who were drilling and putting the cement in should be blamed because the cement wasn’t fully sealed off which is why the oil was able to seek through and get in the water. They were careless and thats who I think should be the most responsible for what went on. They also should be blamed for taking the lives of 4 men that were working and killed in the explosion.