The older model Airbus A320 but just inspected by Lufthansa's technical team on Monday. Not long into the flight, the plane began a controlled steep descent, unannounced and unexplained. There were no radio calls for help from the cockpit or the usual electronic trigger of an emergency signal.
PHOTOS: Plane crash kills 150 in French Alps
The plane vanished from radar, then crashed into the French Alps. The Germanwings Airbus is now in small pieces on this remote mountainside near a ski resort in the south of France.
"This is a tragic moment for Lufthansa and really a dark day in our history," said Heike Birlenbach, Lufthansa vice president for Europe.
Lufthansa owns Germanwings, it's European budget division. There were 150 passengers and crew onboard at the jetliner, including Germans, Spaniards and Turks. There were infants and adults, including16 students and two teachers from Germany on an exchange trip.
"We are in a deep state of shock," said Bodo Klimpel, Haltern mayor. "It's the worst thing imaginable."
The pictures from airports in Spain and Germany are heart wrenching. The information about what happened to their loved ones is slow to be released.
At this staging area down mountain from the crash site, rescue teams gathered, but quickly found there were no survivors to rescue. One of the black boxes has been found and may be the best hope for answers.
For now authorities know that about 45 minutes into flight from Barcelona to Dusseldorf, the plane lost altitude for eight minutes - what they don't know is why.
"For the time being, we're saying it's an accident. There's nothing more we can say," Birlenbach said.
They said the jetliner pilot had 10 years of experience but cannot explain why there was no distress call from the cockpit.
U.S. officials have said they do not suspect terrorism but haven't explained why they ruled it out so quickly when so many questions remain unanswered.