A pilot and passenger are presumed dead after the Friday crash of a helicopter in a south Louisiana marsh, a local government official said.

The sheriff’s office in coastal Lafourche Parish got a call from a witness who saw the aircraft going down about 10:15 a.m.

The wreckage was found in a marshy area about 2:45 p.m., parish President Archie Chaisson told reporters.

“It appears that the aircraft nosedived and basically sunk into the mud, so there’s very little of the aircraft above the water line,” Chaisson said. A part of the fuselage was found about 150 yards away, he said.

The bodies had not been found as of Friday afternoon.

Chaisson said the aircraft was owned by RLC, a privately held helicopter operator. He said the company was not expected to release the names of the victims until Saturday morning.

Representatives of the Federal Aviation Administration and the National Transportation Safety Board were traveling to the area to investigate.