HOUSTON (AP) - An Associated Press investigation shows cutoff
valves like the one that failed to stop the Gulf of Mexico oil
disaster have repeatedly broken down at other wells in the years
since federal regulators weakened testing requirements.
These steel monsters known as blowout preventers guard the mouth
of wells and act as the last defense to choke off unintended
While the precise causes of the April 20 explosion and spill
remain unknown, investigators are focusing on the blowout preventer
on the Deepwater Horizon rig operated by BP PLC as one likely
A detailed AP review of accident reports shows the devices have
played a role in at least 14 accidents, mostly since 2005. And
government and industry reports have questioned the reliability of
blowout preventers for more than a decade.