Fully repairing the USS Bonhomme Richard would have reportedly cost $2.5 billion to $3 billion and take five to seven years.
The fire is the fourth to break out on a Navy ship in recent months.
The agency also found poor communication between the bridge and combat information center contributed to the accident.
The Navy has recovered a $2 million anti-mine pod dropped by one of its helicopters this month off the coast of Virginia.
Damage on some decks spanned the length of the 844-foot ship and reached 106-foot-high ceilings, the CNO said.
Chief of Naval Operations Adm. Mike Gilday said the Navy is launching three investigations into the ship's fire.
Firefighters have extinguished blazes on the Navy amphibious assault ship Bonhomme Richard after four-plus days of efforts.
Forty sailors and 23 civilians have been hurt battling the blaze on the amphibious assault ship Bonhomme Richard.
Hundreds of Navy and other federal firefighters have been fighting for days to put out the blaze.
The sailor was a second-class petty officer, according to data from the Naval Safety Center, which tracks mishaps at sea
As DoD officials look into reports of military participants, legal experts weigh in on what charges they might face.
Jacob Anthony Angeli Chansley, a 33-year-old Navy veteran, refused to take the anthrax vaccine while in the Navy.
Larry Rendall Brock Jr., an Air Force veteran seen brandishing zip tie handcuffs during the pro-Trump siege at the U.S...
Capt. Emily Rainey is scheduled to leave the Army in April after resigning her commission over earlier incidents.
The Marine Corps hit a milestone when three women completed drill instructor school at Marine Corps Recruit Depot San Diego.