Closer Look at the Transocean Deepwater Horizon BOP
Blowout preventers (BOP) are standard safety equipment on any drilling rig, and consist of a series of valves that can be closed to shut-off the flow of oil if the underground pressure of the oil threatens to overstress the rig.
We may never know whether the added safeguard of an acoustic remote shut-off switch could have contained this disaster, but this article offers a closer look: http://gulfcoastmaritime.com/the-gulf-coast/closer-look-at-the-transocean-deepwater-horizon-bop/