Flames have torn through a US warship for a second day as a top navy official revealed a fire suppression system was inoperable when the blaze erupted while the ship was docked in San Diego.
Hundreds of sailors were battling to keep flames away from 3.7 million litres of fuel on board USS Bonhomme Richard.
The US Coast Guard hired an oil clean-up crew to put in place a boom that could be ready if any oil is spilled. It also restricted boat traffic within one nautical mile of the ship and flights flying over the ship.
Meanwhile, acrid smoke from the blaze wafted across San Diego and health officials urged people to stay indoors if they smelled it.
The fire erupted on Sunday morning. At least 57 people have been treated for heat exhaustion, smoke inhalation and minor injuries. Five remained hospitalised under observation on Monday.
Rear Admiral Philip Sobeck said fire temperatures caused the mast to collapse and threaten the central control island.
He said it was too soon to give up on saving the 23-year-old, 255m amphibious assault ship, which has been docked in San Diego since 2018 for maintenance.
The fire was first reported in a lower cargo area where seafaring tanks and landing craft are parked. It appears to have started where cardboard boxes, rags and other ship maintenance supplies were being stored.
Sobeck believes the cardboard and other supplies might have been what first ignited, though the exact cause is still unknown.
The fire suppression system had been turned off because it was being worked as part of the ongoing maintenance, he said.
Australian Associated Press