All nine people on board a sightseeing aeroplane died when it crashed in Alaska.
Clint Johnson, head of the National Transportation Safety Board's Alaska office, said stormy weather was preventing the recovery of bodies from a cliff about 20 miles north-east of Ketchikan.
Attempts to recover the bodies will resume today.
The plane was carrying eight cruise ship passengers and a pilot. It went missing yesterday afternoon and was found against the granite rock face of a cliff, 800 feet above Ella Lake.
Mr Johnson said: " We have nine fatalities."
He said it was too soon to know circumstances of the crash, including whether the DeHavilland DHC-3 Otter turboprop flew into the cliff.
The NTSB was assembling a high-level team to investigate the crash, including three members from Alaska and at least two people from Washington, DC.
"The initial rescue crew that went in had a very tough time because of the terrain," Mr Johnson said. "It's a very steep, mountainous area, and weather conditions caused them to stand down.'
Coast Guard Petty Officer Lauren Steenson said the agency received a report around 2.15pm local time that the plane was overdue.
Troopers said an emergency locator transmitter activated in the Misty Fjords National Monument, and a helicopter pilot spotted the downed aircraft above Ella Lake, about 800 miles from Anchorage.
Promech Air, an airline based in Ketchikan, operated the shore excursion sold through Holland America Line, the cruise ship company said. The eight passengers were guests on the Westerdam, which is on a seven-day cruise that departed from Seattle on Saturday.
"We are incredibly distressed by this situation, and our thoughts and prayers are with those onboard the plane and their families," the company said.
"Holland America Line is extending its full support to traveling companions of the guests involved."
The Ketchikan Daily News reported the Westerdam had been scheduled to leave the city at 1pm local time but it remained in port.
The airline's website advertises tours of the Misty Fjord National Monument in its planes.
"Towering granite cliffs, 1,000-foot waterfalls, lush and remote valleys and serene crystalline lakes make up this incredible landscape," it says.