Following the explosion and fire on the rig, the blow-out preventer on the sea bed should have automatically sealed the well, but it failed, resulting in the massive oil spill.

在油井发生爆炸以及油井起火后，海底上的防喷器本来应该自动将油井封住，但是未能做到这一点，导致大规模的石油泄漏。