...[A]ccording to a team of Norwegian undersea oil-equipment experts who spent six months investigating why the "fail-safe" device did not work...[the] primary cause for that failure...was the blowout preventer's "blind-shear ram" – a massive set of steel jaws intended to completely cut through the drill pipe, crimping it in the process and sealing the well...The reason the shear ram's jaws failed was because they encountered a situation for which they were not designed – a "buckled" section of drill pipe, bowed sideways by the enormous pressure of oil thrusting upward...the investigators said...Besides the "primary cause," investigators identified several other blowout-preventer design problems... • Buckling pipe... • Off-center flaw... • Sequence of other systems... • Control systems... • ROV [remote-operated vehicle] weaknesses... • Backup system standard...