Two seaplanes carrying tourists from the same cruise ship have collided in south-eastern Alaska, with at least four people dead and two missing.
One plane was carrying 11 people when it hit the other, which had five people aboard, near Ketchikan.
Ten of those aboard the first plane survived and were taken to hospital.
Three of those killed were aboard the other aircraft, while it is unclear which plane carried the fourth victim.
Investigators from the National Transportation Safety Board (NTSB) in Washington DC are expected to arrive in Ketchikan later on Tuesday.
Both planes were from the Royal Princess cruise ship which was en route from the Canadian city of Vancouver to Anchorage, Alaska.
The incident occurred in the vicinity of a popular tourist lodge that runs excursions to the nearby Misty Fjords National Monument.
What do we know about the collision?
It happened at around 13:00 (21:00 GMT) on Monday, 10 miles (16km) from Ketchikan, as a plane operated by Taquan Air was returning from the Misty Fjords with ten passengers and a pilot aboard, Princess Cruise Lines said.
The plane operated by Taquan, a regional airline based in Ketchikan, was a single-engine de Havilland DHC-3 Otter.
Coast Guard identified the second plane as a single-engine de Havilland DHC-2 Beaver which was on an independent tour.
Weather conditions in the area at the time saw overcast skies with south-easterly winds of up to 9mph.
Privately-owned vessels in the area helped local and federal rescue services to search for victims.
The 10 people taken to hospital in Ketchikan are said to be in “fair or good” condition.
A Canadian citizen was among the dead, Global Affairs Canada confirmed.
“Our thoughts and sympathies are with the family and loved ones of the Canadian citizen who died in Alaska,” the government agency said in a statement.
“Canadian consular officials in Seattle are in contact with local authorities to gather additional information and stand ready to provide consular assistance as required.”
How have the tour operators responded?
The cruise ship, which departed Vancouver on 11 May and was due to arrive in Anchorage on Saturday, did not leave the area as scheduled on Monday, a passenger told AP.
It was unclear how the collision would affect the rest of the cruise.
“We are deeply saddened to report this news and our thoughts and prayers are with those who lost their lives and the families of those impacted by today’s accident,” Princess Cruise Lines said.
“Princess Cruises is extending its full support to traveling companions of the guests involved.”
Taquan Air announced that it had suspended all flights and was working with the NTSB and other authorities to “examine every aspect” of the collision.
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