- Video report by ITV News Correspondent Dan Rivers
Dozens of people are feared dead after a diving boat caught fire off the coast of southern California.
The bodies of four people have been recovered, but dozens remain missing.
US Coast Guard Lieutenant Commander Matthew Kroll said the four people who had died had drowned.
Search and rescue teams are continuing to look for more than two dozen other people who were aboard the vessel Conception, which burned while anchored off Santa Cruz Island - about 90 miles from Los Angeles.
The Coast Guard said the vessel is believed to have had 38 people on board in total.
The US Coast Guard has sent helicopters, small boats and a patrol cutter out for a search-and-rescue operation.
"Right now they're conducting shoreline searches for any available survivors," Coast Guard Captain Monica Rochester told reporters.
Five crew members sleeping on the top deck of the 75-foot commercial scuba diving vessel were able to jump off the boat before it was engulfed in flames.
They were rescued by a passing boat called The Great Escape, with two suffering minor injuries.
Ms Rochester said the 75ft commercial scuba diving vessel was anchored in Platt's Harbour, about 20 yards off the northern coast of Santa Cruz Island, when the fire ignited at around 3am.
The Conception was on the final day of a Labour Day weekend cruise to the Channel Islands when the fire erupted.
"At 3.15 this morning the Coast Guard overheard a mayday call - one that was unrecognisable through fuzzy white noise.
"The call was garbled, it was not that clear, but we were able to get some information out of it to send vessels on scene," Mr Barney said.
The Ventura County Fire Department said on Twitter that it responded to the fire at around 3.30am.
Fight fighters said flames kept flaring back up when they kept trying to extinguish the blaze.
A survivor's relative speculated a propane gas tank could be responsible for the fire, but the official cause has not been identified.
Asked if the boat operator has any history of violations, Ms Rochester said: "The vessel has been in full compliance."
The boat was operated by a well-known dive company Truth Aquatics, with decades of experience behind them.