Smoke rises from the USS Bonhomme Richard at Naval Base San Diego in July 2020, after an explosion and five-day fire on board the ship. A Navy report has concluded there were sweeping failures by commanders, crew members and others in the arson fire that destroyed the ship.

WASHINGTON — A Navy report has concluded there were sweeping failures by commanders, crew members and others that fueled the July 2020 arson fire that destroyed the USS Bonhomme Richard, calling the massive five-day blaze in San Diego preventable and unacceptable.

While one sailor has been charged with setting the fire, the more than 400-page report, obtained by The Associated Press, lists three dozen officers and sailors whose failings either directly led to the ship’s loss or contributed to it. The findings detailed widespread lapses in training, coordination, communication, fire preparedness, equipment maintenance and overall command and control.

“Although the fire was started by an act of arson, the ship was lost due to an inability to extinguish the fire,” the report said, concluding that “repeated failures” by an “inadequately prepared crew” delivered “an ineffective fire response.”

It slammed commanders of the amphibious assault ship for poor oversight, and said the main firefighting foam system wasn’t used because it hadn’t been maintained properly and the crew didn’t know how to use it. The report is expected to be released Wednesday.

U.S. Navy offiicials on Tuesday said that while crews at sea consistently meet high firefighting standards, those skills drop off when ships move into maintenance periods. The Bonhomme Richard was undergoing maintenance at the time of the fire.

During maintenence there are more people and organizations involved with the ship, including contractors. And the repairs often involve equipment and chemicals that present different hazards and challenges.

The report also found that crew members didn’t ring the bells to alert sailors of a fire until 10 minutes after it was discovered. Those crucial minutes, the report said, caused delays in crews donning fire gear, assembling hose teams and responding to the fire.

Sailors also failed to push the button and activate the firefighting foam system, even though it was accessible and could have slowed the fire’s progress. “No member of the crew interviewed considered this action or had specific knowledge as to the location of the button or its function,” the report said.