Ten years ago, a Germanwings aircraft with 150 people on board crashed into a mountain massif in the French Alps at 700 km/h, with no survivors.

Hundreds of people gathered on Monday near the site in the French Alps where a co-pilot deliberately crashed a plane into the mountainside 10 years ago, killing all 150 people on board.

The Airbus A320 belonging to Lufthansa's low-cost carrier Germanwings met its end on March 24, 2015 near the small Alpine village of Le Vernet while on its way from Barcelona to Düsseldorf. The crash killed all 144 passengers and six crew – a group of people from 20 countries, among them 72 Germans and 50 Spaniards.

Families of the victims in Vernet on Monday marked a minute of silence at 10.41am (09:41 GMT), the exact moment a decade earlier when their loved ones died. Several French, German and Spanish officials laid wreaths in Le Vernet's cemetery, where unidentified victims were buried in a mass grave.

Former mayor Bertrand Bartolini told AFP that visiting the crash site, where rescuers retrieved thousands of body parts amid the wreckage, had deeply scarred him.

It was a "place of absolute horror," he said. "I saw things there that I will never be able to talk about. Grief-stricken families and media soon poured into the remote community, and Bartolini found himself having to sign death certificates for 150 people in multiple copies.

What happened back then?

Investigators have no doubts: the 27-year-old co-pilot, Andreas Lubitz, deliberately steered the Airbus into the mountains to take his own life. This conclusion was reached by both French and German prosecutors, along with the French aviation accident authority.

Analysis of the flight data recorder revealed that Lubitz locked himself in the cockpit after the pilot went to the toilet. The co-pilot then set the altitude to just 30 metres – a manoeuvre he had briefly tested during the outbound flight without being noticed. As the plane descended, Lubitz repeatedly increased its speed. Audio recordings revealed the pilot's futile attempt to open the cockpit door and passengers screaming.

Investigations also uncovered that Lubitz had been forced to interrupt his pilot training in the USA in 2008 due to depression. In the months leading up to the crash, he had consulted several doctors for mental health issues. Despite this, he had withheld a sick note, which included the day of the fatal flight, from his employer.

In the days before the crash, Lubitz had researched suicide methods online and studied the security measures on cockpit doors. Investigators also found an advance directive in his trash, in which he expressed a wish to forgo life-extending treatment if he lost his eyesight.

It was concluded that Lubitz was "obsessed with the unfounded fear of going blind," according to Düsseldorf prosecutor Christoph Kumpa. The co-pilot appeared to believe that his life's purpose – his career as a professional pilot – was over.

Kumpa also rejected claims of technical issues, which had been suggested in a private expert opinion by the Lubitz family and in a TV documentary. These were dismissed by prosecutors as baseless.

What legal consequences followed?

Following the crash, many survivors accused Lufthansa of offering insufficient compensation. In 2016, the airline announced that it had paid more than 11 million euros to the families. Some relatives later secured higher payments through court, though the exact sums were not disclosed.

A class action against the flight school in the USA, where Lubitz had trained, was dismissed. Multiple lawsuits filed by relatives against Lufthansa were also rejected by German courts. The safety of air traffic, the judges argued, is a state responsibility. Flight medical experts are public officials, and Lufthansa had no access to their medical evaluations.

A case against the Federal Aviation Office is still pending. Lawyer Julius Reiter explained that the legal action involves the "determination of responsibility" and potential further pain and suffering compensation. Reiter added that the Federal Aviation Office bears part of the responsibility because the aviation doctors did not consider Lubitz's pre-existing conditions during their assessments. He also argued that the government had failed to implement a European flight safety law effectively.