The same equipment that contributed to the 2010 Deepwater Horizon explosion is still being used in drilling rigs today, according to a Chemical Safety and Hazard Investigation Board report.

The blowout prevention system is a five-story tall series of seals and valves. It was supposed to shear the drill pipe, and short-circuit the explosion, but failed for reasons that were not anticipated and have not been fully corrected since.

The board’s inquiry focused on the blowout preventer and industry safety practices.

The blowout preventer sits on the ocean floor below the drilling rig. Pipe runs throughout it, into the earth and toward oil and gas deposits. When oil or gas comes up the well bore and pipe, the preventer is supposed to cut off the flow higher up to the platform.

In the blowout of BP’s Macondo well, however, lower valves in the blowout preventer closed. Pressure continued to build, bending the drilling pipe. The last line of defense is a blind shear ram in the blowout preventer, but it failed to cut the pipe and instead punctured the bent pipe, sending oil and gas surging to the surface.

Eleven men were killed and nearly 5 million barrels of oil were spilled into the Gulf of Mexico when the well blew out. Improved regulation in deep-water drilling hasn’t fixed all the problems in the industry’s safety systems, the board found. At least one company designed a new blowout preventer, but many rigs are still using the same equipment.

“This results in potential safety gaps in U.S. offshore operations and leaves open the possibility of another similar catastrophic accident,” said Cheryl MacKenzie, lead investigator of the safety board inquiry.

The American Petroleum Institute and the Interior Department countered the report, arguing that serious improvements had been made since the Deepwater Horizon tragedy.

“There is nothing here that hasn’t already been exhaustively addressed by regulators and the industry,” said API spokesman Brian Straessle. “The report appears to omit significant facts and ignores the tremendous strides made to enhance the safety of offshore operations.”

The offshore injury lawyers at Schechter, Shaffer & Harris, L.L.P., Accident & Injury represent workers injured in drilling and other maritime accidents.