Eight passengers and the pilot of a sightseeing plane were killed after the aircraft crashed in rough mountainous terrain in southeast Alaska on Thursday.
Clint Johnson, head of the National Transportation Safety Board's Alaska office, said it was too early to determine the cause and circumstances of the crash, the Associated Press reported.
Visibility was likely between 5 and 10 miles at the time of the crash, suspected to be around 11:20 a.m. local time.
"Cloud bases were between 1,800 and 3,500 feet," AccuWeather Meteorologist Alex Sosnowski said.
Weather prevented any immediate recovery efforts on Thursday. Skies were overcast with rain showers into the afternoon.
While skies will not clear, conditions look to improve slightly for recovery efforts on Friday.
"It'll be cloudy with showers today, but not as wet as Thursday which had heavy and steady rain," AccuWeather Senior Meteorologist John Gresiak said. "Certainly not an optimal day, but it will be better weather to be out."
As efforts continue through the weekend, crews will have an easier time reaching the remote area, roughly 800 miles south of Anchorage, Alaska.
"Things will improve over the weekend with few to no showers and breaks in the clouds," Gresiak said.
The tour was part of a cruise ship excursion run by Holland America Airline. All eight passengers were guests on the cruise, the AP reported.
"All of us at Holland America Line are incredibly saddened by this news. Our thoughts and prayers are with the families and friends of those lost in this tragic accident," the company said in a statement.
Promech Air, the company that provides the tours to the cruise line, has offered similar sightseeing tours for 30 years.
"Discover SE Alaska, the magnificence of Misty Fjords National Monument and the wild Black Bears at Neets Bay with Ketchikan's premier flightseeing company," their website said.