Andreas Lubitz was the boy who grew up dreaming of flying and of one day becoming a pilot.
He went on to fulfil his ambition, but it now appears that it was at the cost of 149 innocent lives.
The circumstances leading up to the Airbus, which the 27-year-old Lubitz was co-piloting, flying into an Alpine mountainside are now the subject of a police investigation.
But suspicion that he may have deliberately flown the plane into the ground, killing all on board, has stunned the people of his home town, and those who watched him learn to fly as a teenager.
The young Lubitz was brought up in the small town of Montabaur, 20 minutes drive from the German city of Koblentz.
With his father a successful business executive and his mother a piano teacher, his family could well afford the cost of flying lessons at his local club, Luftorts Club Westerwald.
Here he first sat in the cockpit of a light aircraft at the age of 14. After a year of instruction under dual controls he was able to fly on his own.
"It was his dream to fly from an early age and it was a dream he began to fulfil here, so when he went on to gain his commercial licence and fly planes like the Airbus he was very happy and proud," said Klaus Radker, the club's chairman.
Mr Radker last saw Lubitz in the autumn of last year, when the Germanwings pilot returned to the club to renew his light aircraft flying licence and take part in the club's barbecue, which he attended with a girlfriend.
Nobody at the club noticed anything strange in his demeanour.
"He seemed normal. Proud of his job after so much training. He seemed happy," said Mr Radker. "I always found him a friendly, if very reserved, person. Open and polite."
Mr Radker said a full and comprehensive investigation must take place before final judgment is passed on his fellow club member.
"Both the people who died and their friends and family survived deserve that, at the very least," he said. "I find it hard to believe that Andreas, who dreamt of flying and of being a pilot, would deliberately fly his plane into a mountain and kill all those people.
"If that is true it also means that the results of all the psychological tests he would have had to take to be a pilot were wrong."
It is now understood that in 2009, Lubitz may have suffered some sort of breakdown that forced him to take a break from his pilot training.
A mother of a school friend of Lubitz's said he had told her daughter that he was suffering from depression.
"Apparently he had a burnout, he was in depression," the girl's mother told a German newspaper. But she added that her daughter had seen him again just before Christmas and that he had appeared normal.
Carsten Spohr, CEO of Lufthansa, Germanwings' parent company, said that Lubitz "took a break in his training six years ago. Then he did the tests (technical and psychological) again. And he was deemed 100pc fit to fly."
But he added: "I am not able to state the reasons why he took the break for several months."
Neighbours of his parents in an affluent suburb on the edge of Montabaur all spoke of a polite, if not particularly gregarious, man.
Johannes Rossbach (23), who lives two doors away, said he would regularly see the pilot jogging through the neighbourhood's quiet streets.
Mr Rossbach said: "He was very polite. He would always say hello and goodbye. There certainly seemed nothing out of the ordinary about him."
He added: "I didn't realise he was a pilot until I heard it yesterday. And today's news is absolutely shocking. I can't believe someone like that would kill 149 other people. It's something that absolutely needs investigating and proving before we can believe it."
Lubitz left Montabaur at the age of 20 in 2007 to begin his commercial pilot's training in the northern German city of Bremen.
It was a year into his training that he appears to have suffered the breakdown and took a break, before returning to qualify. By the time of the accident he was still relatively inexperienced, having notched up only 630 hours of flying time, compared with the flight's captain, who had flown for more than 6,000 hours and had worked for Lufthansa for 10 years.
The Lubitz's half-million euro detached home - a large, grey roof-tiled building from where their son would set out for the short journey to the flying club, set on a plateau on one of the surrounding hills - is now being treated as a potential crime scene.
Yesterday afternoon, groups of plain clothes police officers began carrying out a forensic search of the house. They are also thought to be searching a flat Lubitz rented in Düsseldorf, 84 miles to the north. "We are conducting a search of the parents' home," said Ralf Herrenbrück, the city's chief prosecutor.
"All investigative measures are now under way."
Laura, a neighbour whose brother was in the same year as Lubitz at the high school, added: "I didn't know him well, but to me he seemed very private, perhaps a little bit withdrawn. But who would have guessed at something so shocking happening?" (© Daily Telegraph London)