An Australian cruise ship passenger has died after two sightseeing seaplanes collided in mid-air in Alaska.
The US Coast Guard confirmed on Tuesday one of four people killed was an Australian man.
In the past hour the US Coast Guard for Alaska's 17th District confirmed in a statement that all passengers reported missing had now been found. "Ketchikan Volunteer Rescue Squad located the remaining two missing people near the crash site of the Beaver float plane, Tuesday night."
"In total ten people were rescued and six people were found deceased."
The Australian was initially one of those listed as unaccounted for.
"The Australian unfortunately is one of the people confirmed deceased," US Coast Guard lieutenant Brian Dykens told AAP.
Ten people, all Americans, were rescued and are receiving medical care while four were confirmed dead.
In a press conference on Tuesday local time, the National Transportation Safety Board said they are currently in the process of organising interviews with the surviving pilot and passengers.
"We will want to talk, soon, with the surviving pilot of the TAC-1 plane," a spokesperson said.
"We'll want to talk to the passengers, employees of the two air operators, and we'll also want to talk with other pilots and witnesses that were in the area at the time. We'll be gathering perishable evidence and then we will be requesting additional information from the parties and others that we determine necessary."
NTSB said they will be investigating in to the pilots, the aircraft and the companies who operated the floatplanes. However, the NTSB confirmed there was no cockpit voice recorders or flight data recorders to assist with the investigation, as neither aircraft were required to have the devices.
"We'll be looking at pilot logbooks, and we'll be looking at the training and qualifications of the pilots, as well as any medical issues," the spokesperson said.
"[We will look at] whether flight plans were filed with the company, or the Federal Aviation Administration. We'll also be looking at maintenance records for both aircraft.
"We'll be looking at company operating procedures and whether those operating procedures were followed."
The NTSB confirmed dive teams are continuing to search for two people in the icy cold waters of a southeast Alaska inlet, with one being a Canadian tourist.
However, a Coast Guard official said the remote nature of the search area has created "one of the most difficult conditions" for crews to operate in.
The water temperature off Ketchikan on Tuesday was 8.8 degrees, according to the National Weather Service. The expected survival time in four to 10-degree water is one to three hours, according to the United States Search & Rescue Task Force website.
However, Michael Kahle from the U.S. Coast Guard said officials are holding out hope that those two people would be found alive.
"We are looking for survivors right now," Mr Kahle told Global News.
"It is very cold. Our hope is folks have been able to safely get out of the water… and we'll find them on shore. That's what the shore teams are doing right now, looking for folks that may have made it to shore and are sitting in the tree line there looking for rescue."
The Royal Princess, which can carry up to 3600 people, was among four city-sized cruise ships in the tiny coastal community on Monday.
A popular activity is "flightseeing" in Misty Fjords National Monument to view the lakes, snow-capped peaks and glacier valleys in the wilderness area.
The larger plane, a de Havilland Otter DHC-3 with 10 passengers and the pilot, was returning from Misty Fjord when it collided with another sightseeing plane carrying four passengers from the same cruise ship and a pilot.
The cause of the crash in relatively good weather, high overcast skies with light southeast winds was not known.
The crash occurred about 13 kilometres from Ketchikan, near George Inlet. The planes came down about two kilometres apart with some of the debris field on land.
The smaller plane, a de Havilland DHC-2 Beaver, was partially submerged in the shore of George Inlet after the single-engine plane overturned and hit some trees before crashing, according to Coast Guard Lt Brian Dykens. The larger Otter landed in water and sank, he said.
Investigators from the National Transportation Safety Board were due to arrive later on Tuesday.
Three others who died were among the five people aboard the Beaver, according to Dykens.
Princess Cruises in its release said two passengers and the pilot were among those killed in this plane.
Canadian officials said on Tuesday one of its citizens was among the dead. The Beaver appears to have broken apart in midair, according to Jerry Kiffer, duty incident commander of the Ketchikan Volunteer Rescue Squad.
He said the plane's tail and section of the fuselage were 275m from the aircraft's floats, which landed near shore.
After the crash, the 10 injured passengers were initially taken to a hospital in Ketchikan. Four patients were later transferred to Harborview Medical Center in Seattle, suffering various broken bones, spokeswoman Susan Gregg said.
The Royal Princess left Vancouver, British Columbia, on May 11 and was scheduled to arrive in Anchorage on Saturday.
"We are extending our full support to the investigating authorities as well as the travelling companions of the guests involved," the company said in a statement.
With additional reporting