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indicating the highest level of gas concentration was a contributing cause in the
Deepwater Horizon explosion.

The classification of engine rooms number 3 and number 6 as non‐
classified areas was a possible contributing cause of the Deepwater Horizon
explosion.

The failure to identify the risks associated with locating the air intake of
engine room 3 in close proximity to the drill floor was a possible contributing
cause of the Deepwater Horizon explosion.

The absence of emergency shutdown devices that could be automatically
triggered in response to high gas levels on the rig was a possible contributing
cause of the Deepwater Horizon explosion.

The failure of ABS and Transocean to document which devices were
tested to ensure all devices are tested is a possible contributing cause of the
Deepwater Horizon explosion.

The DP MODU operating philosophy when considering the performance
of an Emergency Shutdown (ESD) is a possible contributing cause of the
Deepwater Horizon explosion.

E. Blowout Preventer

The Panel concluded that the failure of the BOP to shear the drill pipe and
seal the wellbore was caused by the physical location of the drill pipe near the
inside wall of the wellbore, which was outside the blind shear ram cutting
surface during activation on April 20 or April 22.

The elastic buckling of the drill pipe forced the drill pipe to the side of the
wellbore and outside of the BSR cutting surface, and was a contributing cause of
the BOP failure.

The forces generated by the flow from the well and/or forces generated by

the weight of the drill pipe led to the elastic buckling of the drill pipe and was a
possible contributing cause of the BOP failure.

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