BP's failure to learn from past "near misses" and its "insufficient consideration of risk" were major factors in the oil well blowout that led to the biggest US environmental disaster, a panel of US scientists concluded on Wednesday.
The report -- the most comprehensive examination so far of the massive oil spill in the Gulf of Mexico -- also found that numerous technical and operational breakdowns contributed to the Deepwater Horizon oil rig explosion and the massive spill from the Macondo well.
The preliminary study released Wednesday by a committee of experts from the National Academy of Sciences (NAS) faulted BP and its contractors for having failed to learn from earlier problems, and said that proper checks and balances might have prevented the disaster.
"Important decisions made to proceed toward well abandonment despite several indications of potential hazard suggest an insufficient consideration of risks," said Donald Winter, former secretary of the Navy and chairman of the study committee.
US Secretary of the Interior Ken Salazar, who in May commissioned the report, said the document provides a useful guidepost on how officials can improve safety in the oil drilling industry.
"Their independent, science-based analysis of what went wrong in the lead up to the blowout will help guide our continuing efforts to raise the bar for safety and oversight of offshore oil and gas operations, and will be of assistance to other ongoing investigations," Salazar said in a statement.
The document was released by the NAS's National Academy of Engineering, a private, nonprofit group which offers technical advice to the US government.
The group criticized failures by federal officials regulators tasked with overseeing oil drilling entities in the Gulf, including the US Minerals Management Service and other regulatory agencies.
"Flawed decisions were not identified or corrected by BP and its service contractors, or by the oversight process" the NAS panel said.
Though the report said that possible causes for the spill require further investigation, it cited BP and its contractors working on the oil well that exploded on April 20 and triggered the disaster, for a "lack of management discipline."
The panel also faulted their "lack of onboard expertise and of clearly defined responsibilities" and "insufficient checks and balances."
The engineering panel said however that that there are many unanswered questions about the disaster and said it "may not be possible to establish the precise failure mechanism" that triggered the blowout of BP's wellhead, which gushed nearly five million barrels of oil into the sea.
The report also pins some blame on the offshore oil industry as a whole, noting that industry-wide training standards are "relatively minimal" compared to other high-risk industries.
Several non-technical factors also likely contributed to the disaster, it said, including insufficient training of key staff aboard the BP-leased Deepwater Horizon rig and federal regulators' lack of expertise.
The authors did not reach conclusions on why a key set of valves known as the blowout preventer failed to shut down the well and prevent the blast.
Forensic analysis is just beginning to get under way for the device, recovered recently from the Gulf floor.
The committee's final report is due out in June 2011.
Explore further: Oil from Russian trawler wreck reaches Canaries' beaches