Alaskan officials confirmed Sunday that all four people in a helicopter that crashed into a remote lake near the town of Utqiaġvik have died.

The state Department of Natural Resources identified them as employees Ronnie Daanen, Justin Germann and Tori Moore. Pilot Tony Higdon also died, he said.

No ages were given.

The accident happened around 7 p.m. Thursday about 51 miles south-southwest of Utqiaġvik, which claims to be the northernmost city in the US. It was previously known as Barrow.

The Department of Natural Resources said the three state employees, described as geological survey workers, were conducting an airborne field investigation when the aircraft plunged into the large, shallow lake.

His remains were found on Sunday, it said in a statement.

Fog was the predominant weather feature in the region on the night of the accident, according to the National Weather Service.

nbc affiliate KTUU from Anchorage reported the aircraft as a Bell 206L-4 operated by Maritime Helicopters in Homer.

The cause of the accident was being investigated by the National Transportation Safety Board.

«The Department is beginning the process of grieving for our colleagues, supporting our team during this difficult time, and working with partner agencies to learn all we can about this incident,» the Department of Natural Resources said.