Coast Guard and Minerals Management Service officials pressed for answers, who was in charge

The six-member panel of Coast Guard and Minerals Management Service officials pressed for answers about what occurred on the rig on April 20 before it exploded. They required to know who was in charge, and heard contradictory answers.

Over six days in May, faraway from the familiar choreography of Washington hearing, federal investigators grilled employees concerned in the Deepwater Horizon calamity in a chilly, sterile conference room at a hotel close to the airport here.

They short of for more insight into an disagreement on the rig that day between a manager for BP, the well’s title-holder, and one for Transocean, the rig’s owner, and asked Curt R. Kuchta, the rig’s captain, how the crew knew who was in charge.

“It’s pretty well understood amongst the crew who’s in charge,” he said.

“How do they know that?” a Coast Guard investigator asked.

“I guess, I don’t know,” Captain Kuchta said. “But it’s pretty well — everyone knows.”

Looking annoyed, Capt. Hung Nguyen of the Coast Guard, one of the chief federal investigators, shook his head. The switch confirmed a surveillance he had made earlier in the day at the inquiry.

“A lot of activities seem not very tightly coordinated in the way that would make me relaxed,” he said. “Maybe that’s just the way of business out there.”

Investigators have paying attention on the minute-to-minute decisions and breakdowns to know what led to the explosion of the Deepwater Horizon, killing 11 people and setting off the largest oil spill in United States history and an environmental tragedy. But the lack of coordination was not limited to the day of the detonation.

New government and BP credentials, interviews with experts and testimony by witnesses present the clearest indication to date that an assortment of oversight agencies granted exceptions to rules, allowed risks to build up and made a disaster more likely on the rig, particularly with a mix of different companies operating on the Deepwater whose interests were not always in sync.

And in the aftermath, arguments about who is in charge of the cleanup — often a signal that no one is in charge — have led to delays, distractions and disagreements over how to cap the well and defend the coastline. As a result, with oil continuing to gush a mile below the surface in the Gulf of Mexico, the laws of physics are largely in control, creating the daunting challenge of trying to plug a hole at depths where equipment is straining under more than a ton of pressure per square inch.

Tad W. Patzek, chairman of the Petroleum and Geosystems Engineering Department at the University of Texas, Austin, has analyzed reports of what led to the explosion. “It’s a very complex operation in which the human element has not been aligned with the complexity of the system,” he said in an interview last week.

His conclusion could also apply to what occurred long before the tragedy.