ANCHORAGE, Alaska (AP) — One of the two pilots aboard an airplane carrying fuel reported there was a fire on the airplane shortly before it crashed and burned outside Fairbanks, killing both people on board, a federal aviation official said Wednesday.

The pilot had made radio contact about the in-fight emergency shortly after taking off Tuesday, said Clint Johnson, head of the National Transportation Safety Board’s Alaska regional office. They were attempting to return to Fairbanks International Airport when they lost contact, he said.

The plane crashed about 7 miles (11 kilometers) outside Fairbanks, hitting a steep hill and sliding down an embankment to the bank of the Tanana River, bursting into flames. Alaska State Troopers say no survivors were found.

Troopers said recovery efforts would resume Wednesday with the aid of dogs, but noted thin ice and open water on the river were making their efforts difficult. The pilots’ names have not been released.

“The remains that have been recovered will be sent to the State Medical Examiner’s Office for positive identification,” troopers said in a statement.

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The plane departed Fairbanks just before 10 a.m., loaded with 3,200 gallons (12,100 litres) of heating oil for Kobuk, an Inupiat village of less than 200 people located about 300 miles (480 kilometers) northwest of Fairbanks.

Johnson said there was also about 1,200 gallons of aviation fuel aboard the C54D-DC Skymaster plane, a World War II-era airplane that had been converted to a freighter.

It is difficult and expensive to get fuel to rural Alaska villages, which are remote and difficult to reach because of the state’s limited road system. The Northwest Arctic Borough said heating fuel in Kobuk was $15.45 a gallon in 2022.

The Alaska Energy Authority said barges usually deliver fuel to coastal communities. But in villages where barges can’t run or it’s not economically feasible, air tankers will deliver fuel — but that is even limited by sea or river ice, water levels or ice road availability.

The C54D-DC is a military version of the Douglas DC-4, which was a World War II-era airplane. The website www.airlines.net said standard passenger seating for a DC-4 was 44 during its heyday, but most have been converted to freighters.

The NTSB has three investigators on the scene.

The plane was registered to Alaska Air Fuel of Wasilla. Phone messages left for the company have not been returned.