A US panel has spread blame for the deadly Gulf of Mexico oil spill beyond BP to Halliburton and Transocean, accusing all three of "systemic" management failures that could happen again.
The presidential commission's assessment was part of its final report on the deadly April blowout of BP's Macondo well, which killed 11 workers and spewed 4.9 million barrels of oil into the Gulf of Mexico over three months.
It said oil services giant Halliburton and offshore drilling group Transocean were also very much at fault in ignoring key warnings and failing to take the necessary precautions to avert the massive spill.
The blowout "was the product of several individual missteps and oversights by BP, Halliburton and Transocean, which government regulators lacked the authority, the necessary resources and the technical expertise to prevent," read the advance chapter. The full report is due out next week.
Transocean owned the BP-leased Deepwater Horizon platform that sank in the accident. In October, Halliburton admitted skipping a key cement test before the blowout, but blamed BP for not testing the integrity of the job.
The root causes of the blowout were "systemic and, absent significant reform in both industry practices and government policies, might well recur," the report said.
"Whether purposeful or not, many of the decisions that BP, Halliburton and Transocean made that increased the risk of the Macondo blowout clearly saved those companies significant time (and money)."
Saying it supported the presidential commission's probe into the incident, BP stressed that preliminary findings concluded that "the accident was the result of multiple causes, involving multiple companies."
The beleaguered firm said it was working with regulators and the industry "to ensure that the lessons learned from Macondo lead to improvements in operations and contractor services in deepwater drilling."
It cited launching a new division devoted to safety and operational risk that reports directly to the firm's CEO Bob Dudley and will provide "independent oversight" of safety-related operational decisions.
The findings "only compound our sense of tragedy because we know now that the blowout of the Macondo well was avoidable," said former Florida senator Bob Graham, the commission's co-chair.
"This disaster likely would not have happened had the companies involved been guided by an unrelenting commitment to safety first. And it likely would not have happened if the responsible governmental regulators had the capacity and will to demand world class safety standards."
According to the report, the Macondo well blew out when a series of "separate risk factors, oversights and outright mistakes combined to overwhelm the safeguards" designed to prevent such an event.
"But most of the mistakes and oversights at Macondo can be traced back to a single overarching failure -- a failure of management," it added.
"Better management by BP, Halliburton and Transocean would almost certainly have prevented the blowout by improving the ability of individuals involved to identify the risks they faced, and to properly evaluate, communicate and address them."
Former Environmental Protection Agency (EPA) administrator William Reilly, another co-chair of the commission, pointed to a "system-wide problem."
The seven-member panel was set up by US President Barack Obama and tasked with finding out what caused the accident.