NEW ORLEANS — A federal report released Wednesday blames a poor “safety culture” for the mistakes that led to a deadly 2013 explosion at a Louisiana petrochemical plant.

Two people died in the ground-rattling June 2013 blast, which witnesses said sent flames as high as 200 feet over the Williams Olefins Plant in Geismar. The blast happened after the rupture of a “reboiler” at the plant.

“In the years leading up to the incident, Williams Geismar exhibited characteristics of a weak process safety culture,” the U.S. Chemical Safety Board report said.

The report listed deficiencies including untimely or incomplete safety reviews, inadequate analyses of equipment safeguards and failures to follow some U.S. Occupational Safety and Health Administration regulatory requirements.

The report said plant personnel failed to recognize the danger of having certain valves closed at a critical time, isolating the reboiler from a device designed to relieve the pressure that led to the rupture.

Last month, a jury awarded a total of $13.6 million to four men injured in the explosion, finding that officials at the plant and its parent company were negligent and knew with substantial certainty that the deadly fire could occur.

The company announced plans for an appeal after the verdict, saying that nothing about the accident was intentional.

An attorney representing injured workers, Kurt Arnold, said in an email on Wednesday that the report “confirms what we already know — that Williams’ utter disregard for safety leads to senseless, preventable disasters.”

The report says safety management has improved since the explosion, but also recommends more safety improvements; among them, the formation of a safety committee of Williams employees.

The Tulsa, Oklahoma-based company responded with a statement Wednesday saying it is “committed to continuous improvement of its process safety programs.”

“Williams is in receipt of the report and intends to address the findings and recommendations of the CSB in order to enhance process safety performance at the Geismar facility,” the statement said.