What went wrong at oil rig?

May 13, 2010 at 12:00a.m.

Associated Press

WASHINGTON

Bad wiring and a leak in what’s supposed to be a “blowout preventer.” Sealing problems that may have allowed a methane eruption. Even a dead battery, of all things.

New disclosures Wednesday revealed a complex cascade of deep-sea equipment failures and procedural problems in the oil-rig explosion and massive spill that is still fouling the waters of the Gulf of Mexico and threatening industries and wildlife near the coast and on shore.

The public also got its first look Wednesday at oil gushing from the broken pipe that rests nearly a mile under water as BP PLC, the well’s operator, released a video taken by a remotely controlled camera. Oil flowing from a break in the yellowish pipe becomes lighter in color as it mixes with natural gas. Over the past 21 days, more than 4 million gallons of oil have been released.

A litany of worrisome events and findings that were at play on the night of the well explosion and pipe rupture was described in internal corporate documents, marked confidential but provided to a House committee by BP and by the manufacturer of the safety device. Lawmakers released them at a House hearing.

A senior BP executive, Lamar McKay, cautioned, “It’s inappropriate to draw any conclusions before all the facts are known.” But the documents established the firmest evidence to date of the sequence of catastrophic events that led to the explosion and worsening spill, a series of failures more reminiscent of the loss of the space shuttle Challenger than the wreck of the Exxon Valdez.

Like the 1986 Challenger disaster, the investigation into the Gulf spill may well show that complex and seemingly failproof technical systems went wrong because of overlooked problems that interacted with one another in unexpected ways.