Safety valve failure at heart of BP oil spill, study finds
A trapped piece of drill pipe prevented a fail-safe device from stopping last year's massive BP Gulf oil spill, a US government investigation has found.
Its report said the device, known as a blow-out preventer, failed to work properly because the piece of drill pipe kept its blind shear rams from sealing the well around the time of the April 20 oil rig explosion off the coast of Louisiana.
