French officials say the co-pilot of a German passenger jet that crashed in the French Alps apparently wanted to "destroy the plane."
Marseille Prosecutor Brice Robin said on March 26 that evidence from the cockpit voice recorder suggested the German co-pilot deliberately crashed the Airbus A320, which slammed into a mountainside during a flight from the Spanish city of Barcelona to Duesseldorf.
All 150 people aboard were killed in the worst airline disaster in Western Europe since 2008.
Lufthansa, which operates the budget airline Germanwings, said no distress signal was sent and the crew did not respond to attempts at contact from ground control as the jet descended for eight minutes before the crash on March 24.
Robin said the co-pilot, identified as 28-year-old German citizen Andreas Lubitz, began the descent "intentionally" while alone at the helm.
Robin said there was "absolute silence in the cockpit" as the pilot fought to get back in.
Under strengthened security measures introduced after the September 11, 2001 hijacking attacks in the United States, authorization to open a cockpit door can only come from inside and from a pilot.
"The most plausible interpretation is that the co-pilot through a voluntary act had refused to open the cabin door to let the captain in," the prosecutor said. "He pushed the button to trigger the aircraft to lose altitude."
"He operated this button for a reason we don't know yet, but it appears that the reason was to destroy this plane," he added.
Robin added that Lubitz was conscious and continued breathing normally before impact.
He said there was "no reason to suspect a terrorist attack."
The passengers were likely not aware of a crash until just before impact, the prosecutor said.
Media reported the screams of passengers could be heard on the audio recording from the plane's black box during the last seconds before the plane impacted.
He also said German authorities were expected to provide additional information on Lubitz later on March 27-28.
Meanwhile, German Interior Minister Thomas de Maiziere said that current information suggested that the co-pilot "does not have a terrorist background."
German Transport Minister Alexander Dobrindt said the French prosecutors' assessment that the plane was deliberately put into descent was "plausible according to our experts."
"According to current knowledge we assume that the captain was actively barred from accessing the cockpit," he added.
Spainish Prime Minister Mariano Rajoy said he was "deeply shaken" by the French prosecutor's finding.
Lufthansa chief executive Carsten Spohr said he was "stunned" by suggestions the co-pilot deliberately crashed the plane.
Spohr said the airline had “no indication” of why he would have done so.
He said pilots undergo a yearly medical examination but that doesn't include psychological tests.
French President Francois Hollande, German Chancellor Angela Merkel, and Rajoy travelled to the crash site in a remote Alpine region on March 25 to pay tribute to the victims, most of whom were German or Spanish.
After the revelations about the actions of the plane's co-pilot became known, Merkel said on March 26 said the findings added an "absolutely unimaginable dimension" to the tragedy.
French police at the crash site about 2,000 meters above sea level said no one had survived and it would take days to recover the victims' remains due to difficult terrain, snow, and incoming storms.
Among the victims were 16 German teenagers and two teachers from a high school who were on their way home after a weeklong exchange program near Barcelona.
A Lufthansa flight took about 60 relatives of the victims from Barcelona to France on March 26 to visit the scene of the disaster.
The Alpine disaster was the first crash of a large passenger jet on French soil since the Concorde disaster just outside Paris nearly 15 years ago.