The parents of an American victim of the French Alps plane crash said today they feel sadness for the parents of the co-pilot rather than feeling anger for the loss of their son.

French prosecutors say a young German co-pilot barricaded himself alone in the cockpit of Germanwings flight 9525 and apparently set it on course to crash into an Alpine mountain, killing all 150 people on board including himself on Tuesday.

The prosecutors have offered no motive for why Andreas Lubitz, 27, would take the controls of the Airbus A320, lock the captain out of the cockpit and deliberately set it veering down from cruising altitude at 3,000 feet per minute.

German police have searched his home for evidence that might offer some explanation.

Robert Tansill Oliver, a Jehovah's Witness, lost his 37-year-old son Robert Oliver Calvo in the Germanwings plane crash on Tuesday.

"I don't feel anger. I'm really sad for the parents of that young pilot. I mean, I can't imagine what they're going through right now. As well as companions here, they are all feeling, hurting. No we don't feel anger at all. As Witnesses we are peace makers. We are sorry it happened of course. We blame what the bible calls the rule of the world. We are angry with the rule of the world," Oliver told reporters outside the Rey Don Jaime hotel where the relatives of the victims are staying.

Oliver says he's not interested in launching legal action over the loss of his son.

"We're not eager to take any legal action. We're mostly interested in sharing hope and comfort and of course being with our family, our niece and our grandchildren, comforting them," he said.

Robert Oliver Calvo was a Barcelona-born American citizen.

He worked for the Barcelona-based clothing company Desigual, and left behind a wife and two children.