The chief executive of German airline Lufthansa says it will take a "long, long time" to determine exactly what led a co-pilot to crash a jetliner into the French Alps, killing all 150 people aboard the flight.
Lufthansa CEO Carsten Spohr paid his respects to the victims Wednesday at the site of the March 24 Germanwings crash in remote southeastern France.
Spohr ignored a barrage of questions from reporters about why the airline certified the co-pilot, 27-year-old Andreas Lubitz, as fit to fly when Lubitz told the airline during his 2009 flight school training that he had had a "serious depressive episode."
"We are learning more every day about the cause of the accident," Spohr said, "but I think it will take a long, long time for everybody, all of us, to understand how this could happen."
Spohr and Thomas Winkelmann, the chief executive of Germanwings, Lufthansa's budget carrier subsidiary, laid flowers at a stone monument to the crash victims.
Cell phone video
Meanwhile, questions persist about reports in the German daily Bild and the French magazine Paris Match about a video they say was taken by someone inside the cabin of the doomed plane shortly before it crashed. The publications say their reporters were shown the video, which they said was found on a memory chip that could have come from a cellphone.
Marseille Prosecutor Brice Robin, who is overseeing the French criminal investigation into the crash, told The Associated Press that investigators had found no such video. But in a statement Wednesday, he left open the possibility that such video had been found but not given to authorities.
"In the hypothesis that someone is in possession of such a video, he or she should submit it immediately to investigators,'' he said.
Frederic Helbert, the Paris Match reporter who saw the video, said on the magazine's website Wednesday that he was "offered the possibility to view it'' after working with unnamed intermediaries linked to unnamed people at the search site.
Helbert said the video was shot from the back of the plane. He said no one is identifiable but it conveys "the human dimension of the panic'' right before the crash.
'It's a video that's distressing, it's a video that gives you the shivers, it's a video that I've watched, that several of us have watched, again and again dozens of times," he told Reuters. "You should be aware that you can't identify any of the people in the video, it's not sensationalist.... But it's the noise that's terrible. It's the human dimension of panic, of distress of the shouts of people in the plane that makes it terrible.''
Families and friends of victims gathered near the ravine where the Airbus A320 jet went down. Spohr expressed deep sorrow over the crash and promised his company will help the families of the 150 victims for "as long as is possible."
Investigators said Wednesday that they have finished the search for human remains at the site. They are still looking for one of the "black box" recorders with crucial flight data information that could help them determine what happened in the final minutes before the crash.
French prosecutors said Monday that Lubitz had suicidal tendencies in the past, but appeared to be stable at the time of the crash.
French President Francois Hollande said all the victims on the flight from Barcelona, Spain to the German city of Dusseldorf would be identified by DNA samples by the end of this week.
French officials said the plane's cockpit voice recorder indicated that Lubitz locked pilot Patrick Sondheimer out of the cockpit when he left to go to the lavatory before deliberately setting the plane to descend into the mountainside.
Prosecutors said they have not yet found any motive for Lubitz's action.
Some material for this report came from AP and Reuters.