Last-ditch efforts to control the flow at surface and at the subsea BOP were made, as follows:
1) The lower annular in the subsea BOP and the Diverter packer which closes around
the drill pipe just below the rig floor were shown to have been activated by indicator
lights in the vessel bridge space BOP control panel.11 Unsuccessful diversion of the
escaping high momentum and pervasive well fluids allowed internal combustion (IC)
engine ingestion of flammable vapors causing engine overspeed. Ignition of the
flammable vapor cloud lead to multiple explosions, loss of power, and a massive fire
plume that consumed the drilling rig. Emergency Shutdown (ESD) functions were
not programmed to be automatically initiated on activation of rig combustible gas
detectors, nor was the platform audible general alarm automated.