An Australian man who was a 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.
The Australian was initially listed as missing. "The Australian unfortunately is one of the people confirmed deceased," US Coast Guard lieutenant Brian Dykens told AAP.
Ten people were rescued and are receiving medical care while four were confirmed dead.
The nationalities of the people from both planes are 14 Americans, a Canadian and an Australian.
Two people are missing.
The Australian Department of Foreign Affairs and Trade said it was providing consular assistance to the family of an Australian man who died in Alaska.
“For privacy reasons we are unable to provide further information,” a statement said.
Dive teams are searching for the missing pair in the icy cold waters of a southeast Alaska inlet on Tuesday after Monday's collision near Ketchikan, a popular destination for cruise ships in Alaska.
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 flight-seeing in Misty Fjords National Monument to view the lakes, snowcapped peaks and glacier valleys in the wilderness area.
The collision occurred when a larger de Havilland Otter DHC-3, carrying 10 passengers and the pilot and returning from Misty Fjord collided with a smaller DHC-2 Beaver with 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.
It happened about 13 kilometres from Ketchikan, near George Inlet. The planes came down about two kilometres apart with some of the debris field on land.
One plane ‘broke apart mid-air’
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 (local time).
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 (local time) 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, in British Columbia, on May 11 (local time) and was scheduled to arrive in Anchorage on Saturday (local time).
"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.