California officials have begun the process of identifying the victims of a boat fire that is suspected to have claimed 34 lives.
Santa Barbara County Sheriff Bill Brown said that DNA samples would be required from the family of presumed victims to identify them.
Authorities have moved from search-and-rescue operations to a recovery effort. Only five people survived, all crew.
The scuba-diving boat caught fire on Monday as passengers slept below decks.
Twenty bodies – 11 females and nine males – have been recovered but more remain in the submerged wreckage, officials said on Tuesday.
Divers will attempt to stabilise the 75ft-long (23m) vessel, the Conception, to recover the remaining victims.
The vessel is upside down in more than 60ft of water, officials said.
When asked why DNA material would be necessary, Sheriff Brown told reporters it was an “inordinately hot fire and the bodies do exhibit signs of extreme thermal damage”.
According to preliminary reports, Sheriff Brown said, a 17-year-old and several people in their 60s were probably aboard the recreational diving vessel when it caught fire.
The brother of one marine biologist – 41-year-old Kristy Finstad – told US media she had been leading a dive trip and was presumed dead.
No cause of the fire has yet been determined.
What have authorities said?
Captain Monica Rochester of the US Coast Guard said search-and-rescue operations were suspended on Tuesday morning after a reconnaissance aircraft flew over the wreck and found “no additional signs of distress or debris”.
The debris field spanned nearly 1.5 miles (2.4km), said Sheriff Brown. He said more than 160 miles of ocean had also been searched.
Cpt Rochester told reporters the boat had had an “open berthing” plan, meaning there were no locked doors onboard and curtains were used to section off different compartments, such as the sleeping quarters.
She added that smoke detectors and fire-fighting systems were required to be on the boat, which had passed its most recent annual screening.
When asked if the crew were required to post a night watch, Capt Rochester said that matter was still under investigation.
How did the crew survive?
Five members of the boat’s crew escaped the blaze and were able to steer another vessel to a nearby boat, the Grape Escape, where they called emergency services for help.
Sheriff Brown said the captain appears to have jumped into the water with others fleeing the burning boat.
The Conception was split into three decks, Sherriff Brown said, with the passengers being given the bottom level as their chambers.
The middle deck housed the boat’s galley and salon, and the top deck was the crew’s quarters and the boat’s bridge, he said.
He said it was “perfectly normal for the crew to be up on that assigned deck” and closest to an exit when the fire broke out.