WEST VIRGINIA (NEWSCHANNEL 3) - Federal investigators are trying to figure out what caused a plane crash that killed a West Michigan father and son.

A relative confirms the victims are Michael and Andrew Land of Richland.

Michael was the President and General Manager of U.S. operations at the pharmaceutical testing company Phadia. It's headquartered in Portage.

Both Michael and Andrew died when their single-engine plane crashed in West Virginia Sunday afternoon.

Police say the men were visiting for the holiday weekend and were headed back to Kalamazoo, but their plane went down shortly after take-off.

The debris is scattered over 200 yards and investigators say they found no signs of fire or explosion.

A more detailed report should be out next week.