Germanwings Co-Pilot Appears to Have Deliberately Crashed Plane, According to French Prosecutor

Germanwings flight 4U9525 appears to have been deliberately crashed into the French Alps by one of its pilots, according to the Marseilles prosecutor currently working on the case.

Brice Robin spoke at a press conference today, during which he described the chilling series of events that led to the disaster. There were 144 passengers and six staff on board when the plane crashed in southern France. No survivors have been found.

For the first 20 minutes after taking off from Barcelona, the two pilots who were operating the Airbus A320 had a "cheerful and polite" conversation, according to Robin. The captain then gave instructions to his co-pilot about landing in Düsseldorf and the copilots' answers to the instructions were "laconic," according to the prosecutor.

Robin then explained that the captain had to leave the cockpit to "satisfy natural needs." During that time, the co-pilot initiated the plane's descent, by "pushing the flight monitoring system's buttons" for reasons that remain unknown. When the captain come back, he was apparently locked out of the cockpit.

"The most plausible interpretation is that the co-pilot, through a deliberate omission, refused to open the door of the cockpit to the captain and activated the loss of altitude button for a reason that we are totally unaware of, but that can be interpreted as an intention to destroy this aircraft," Robin said.

Robin also revealed the co-pilot was Andreas Lubitz, a 28-year-old German citizen, and added that German authorities would be in charge of giving background on him.

PHOTO — AirLive.net (@airlivenet)March 26, 2015

The prosecutor continued that on the recording you can hear the co-pilot breathing until the plane crashes, which excludes the thesis of a sudden faint. Robin added that at this stage there was no indication that this was a terrorist attack.

The German co-pilot in the cockpit remained conscious until impact, with Robin stating: "He was breathing normally, he did not utter a single word." The prosecutor added that during the 10 minutes that it took for the plane to finish its trajectory and eventually plummet into the mountains, not one sound was heard inside the cockpit, and the only noises that could be heard were breathing and the sound of panicking passengers. "We could hear the cries minutes before the plane crashed," Robin said.

On the recording, increasingly frantic knocks can be heard on the cockpit's door. On Wednesday, a senior investigator said that the captain had begun attempting to break down the door. In reply to a journalist's question, Robin told the assembled media that the "victims only realized what was going on at the last moment."

When questioned about the possibility of this being a suicide, Robin responded: "When you commit suicide, you die alone. With 150 on the plane, I wouldn't call that suicide."

Related: German plane crashes in French Alps with 150 people on board. Read more here.

Before holding the press conference Robin contacted the victims' grieving families and told them what he later disclosed to the public.

More details are emerging about Lubitz, the man accused of deliberately crashing the plane. The co-pilot reportedly wanted to fly planes from the time he was a teenager, and joined Germanwings in September 2013, straight after finishing flight school.

Klaus Radke, the head of a flight club in Lubitz's hometown Montabaur, western Germany, told Reuters that the co-pilot was "a completely normal guy."

Lubitz received his first flying license from the club and returned later for a refresher course. "I got to know him, or I should say reacquainted with him, as a very nice, fun and polite young man," Radke said.

Another member of the club, Peter Reucker, told Reuters that he couldn't comprehend what had happened. "I don't have any explanation for this. Knowing Andreas, this is just inconceivable for me."

He added: "Andreas was a very nice young man who got his training here and was a member of the club. He was a lot of fun, even though he was perhaps sometimes a bit quiet. He was just another boy like so many others here."

The house believed to belong to Lubitz was searched by police this afternoon.

Media gathers outside the house where — Imelda Flattery (@Imeldaflattery)March 26, 2015

Lubitz had flown 630 hours as a commercial pilot — a relatively low amount.

The captain who was with him had 6,000 hours of flying experience, and had worked for Lufthansa for the previous decade.

German Interior Minister Thomas de Maiziere said that Lubitz had no known association with any terrorist groups.

Speaking at a press conference in Cologne, Lufthansa CEO Carsten Spohr said that this morning's revelations about the tragedy had left him "speechless."

"I can only repeat what I have said over the last few days. We are really deeply shocked and I would not have been able to imagine that the situation would have got even worse."

He also dismissed the suggestion that the airline's safety controls were inadequate. "What has happened here is a tragic individual event," he said. "We are trying to deal with an enigma."

Spohr said that all pilots undergo annual medical checks, but no further special psychological assessments happen beyond their training period. "The two pilots in question were successful in all the procedures," Spohr said. According to the CEO, Lubitz passed with "flying colors."

Spohr also mentioned that Lubitz had taken a break of several months from his training, which he began in 2008. The CEO stated that he couldn't say why Lubitz took that period off. A journalist for Der Spiegel reported that friends of Lubitz had said the hiatus was a result of "burn-out syndrome."

German Chancellor Angela Merkel offered condolences to the families who have lost loved ones in the crash. "It is difficult to measure the suffering that this catastrophe has brought to so many families," she said in a news conference on Thursday afternoon. "Today, we now have received news that this tragedy has been given a new, immeasurably incomprehensible dimension."

Germanwings released a short statement before announcing the press conference. "We are shaken by the upsetting statements of the French authorities," it read. "Our thoughts and prayers continue to be with the families and friends of the victims."

Family and friends of the victims have been gathering in the town of Seyne-les-Alpes, France, where there will be a memorial ceremony. The French Interior Ministry has said that they will make French, German, and Spanish doctors and psychologists available for the families and friends of those killed.

Some local residents have reportedly offered to host the mourners.

As a reaction to the crash, some airlines have announced that they will implement a requirement that at least two crew members remain in the cockpit at any one time going forward. Airlines introducing these changes include Easyjet, Canada Air, and Norwegian Air Shuttle.

Related: Germanwings pilot reportedly locked out of cockpit before crash that killed 150 people. Read more here.

VICE News' Melodie Bouchaud contributed to this report.

Follow Sally Hayden on Twitter: @sallyhayd