The crew of the Deepwater Horizon had a number of warning signs extending over five hours that conditions were worsening deep underwater before the oil rig exploded in the Gulf on April 20, BP's own investigators told a House inquiry into the cause of the deadly accident.
Details of BP's internal investigation provide fresh information about the extent of failures on the ill-fated rig, but the oil company's inquiry skirts the central question: Why were those warnings ignored?
In yet another blow, a government report alleges that drilling regulators have been so close to the industry that they've been accepting gifts from oil and gas companies and even negotiating to go work for them.
BP's next effort to stop the gushing oil well, perhaps today, is to involve a procedure called a "top kill," in which heavy mud and cement are to be shot into the well to plug it up.
In its report to Congress, BP said crews noticed unusual pressure and fluid readings that should have alerted them not to remove heavy drilling lubricants known as "mud" from the well -- a move that apparently allowed a sudden upwelling of gas that led to the explosion and sinking of the rig about 50 miles from the Louisiana shoreline.
The first warning came five hours before the explosion, said congressional investigators with the oversightsubcommittee of the House Energy and Commerce Committee in a memo released Tuesday night.
There was evidence that throughout the day, crews failed to follow proper procedures for critical activities, and had readings 51 minutes before the explosion that showed more fluid was being pumped out of the well than was being pumped in.
"It appears that BP and Transocean had multiple warnings before the rig exploded," said Rep. Henry Waxman, D-Calif, chairman of the House Energy and Commerce Committee. "We need to know why they didn't shut down the well while there was still time."
Even though pressure readings indicated "a very large abnormality," BP continued to replace drilling mud with seawater. That move, BP's team told the subcommittee's investigators, may have been a "fundamental mistake."
There are clear indicators they should have stopped, said Bob Cavnar, a Houston engineer who's been involved in oil and gas exploration.
"These wells talk to you all the time, and if you're not paying attention to the language they speak, sometimes they bite you," Cavnar said. "What killed these guys was complacency. It was shouting at them, but they ignored it."
In Washington, the Obama administration said it has been laboring to root out problems at the federal agency that regulates offshore drilling.
In at least one case, according to a new report from the Interior Department's acting inspector general, an inspector for the Minerals Management Service admitted using crystal methamphetamine and said he might have been under the influence of the drug the next day at work.
The report began as a routine investigation, the acting inspector general, Mary Kendall, said in a cover letter to Interior Secretary Ken Salazar, whose department includes the agency.
"Unfortunately, given the events of April 20 of this year, this report had become anything but routine," she wrote. Her biggest concern is the ease with which minerals agency employees move between industry and government, Kendall said.
While no specifics were included in the report, "we discovered that the individuals involved in the fraternizing and gift exchange - both government and industry - have often known one another since childhood," Kendall said.
Their relationships took precedence over their jobs, Kendall said.
The report follows a 2008 report by then-Inspector General Earl Devaney that decried a "culture of ethical failure" and conflicts of interest at the minerals agency.
The report said that employees from the Lake Charles, La., MMS office had repeatedly accepted gifts, including hunting and fishing trips from the Island Operating Company, an oil and gas company working on oil platforms regulated by the Interior Department.
Taking such gifts "appears to have been a generally accepted practice," the report said.
Two employees at the Lake Charles office admitted using illegal drugs, and many inspectors had e-mails that contained inappropriate humor and pornography on their government computers, the report said.
Kendall recommended a series of steps to improve ethical standards, including a two-year waiting period for agency employees to join the oil or gas industry.
The Associated Press contributed to this report.