A search and rescue operation is continuing in the French Alps, as officials attempt to understand exactly what caused Tuesday's plane crash tragedy that is thought to have killed 150 people.
An Airbus A320 aircraft crashed in a remote and mountainous region of southern France just before 11am, with 144 passengers and six crew members on board. The Germanwings flight was traveling from the Spanish city of Barcelona to Düsseldorf, Germany.
The crash occurred just over 90 miles north of Nice, between the cities of Digne-les-Bains and Barcelonette. The impact reportedly happened after eight minutes of descent, and the plane sent out no distress signal, but further evidence is still emerging. One of the aircraft's black box flight recorders has been recovered and is currently being analyzed.
According to the New York Times, evidence from a cockpit voice recorder indicated one pilot was locked out of the cockpit before the plane's descent and unable to get back in.
A senior military official involved in the investigation told the Times there was a "very smooth, very cool" conversation between the pilots during the early part of the flight, followed by a panicked effort by one pilot to reenter the cockpit.
"The guy outside is knocking lightly on the door and there is no answer," the investigator told the Times. "And then he hits the door stronger and no answer. There is never an answer… You can hear he is trying to smash the door down."
In a press conference on Wednesday afternoon, Rémi Jouty, the head of the French "Bureau d'enquêtes et d'Analyses" (BEA) said that they had been able to get data from the first black box. However, he added, "so far, we don't have enough evidence to support assumptions about the reasons explaining why the aircraft crashed." Jouty said the BEA had managed to extract an audio file from the cockpit voice recorder, but refused to go into more detail.
"At this point, we are not shutting any thesis down," Jouty said. Jouty added that he was "optimistic" about finding the second box, and that the BEA in conjunction with its German and Spanish counterparts.
Speaking from Cologne, Germany, where the airline is based, Germanwings CEO Thomas Winkelmann mentioned the cancelation of some further flights because crew members didn't want to fly for personal reasons and he said that this was "understandable."
"We are a small family," Winkelmann said. "Everybody knows everyone else in Germanwings."
A full list of the passengers and staff who were on board has yet to be released, but none are expected to have survived.
At least 72 of the 144 passengers are believed to have been German. These included a group of 16 students and two teachers from Joseph Koenig high school in Haltern am See. The pupils had been participating in an exchange program with a school near Barcelona.
Germanwings, the budget airline owned by national carrier Lufthansa, has reportedly offered to fly the families of the students to the crash site, but none have so far availed themselves of the offer.
British Foreign Secretary Philip Hammond has said that there were at least three British citizens on board the plane. At least 35 passengers are thought to have been Spanish, while other individuals came from countries including Colombia, Mexico, Japan, Israel, Argentina, Venezuela, and the US. Two babies were also apparently among those on the plane when it went down.
German, French, and Spanish leaders Angela Merkel, Francois Hollande, and Mariano Rajoy visited the scene of the crash, where they were briefed on the search operation and thanked the rescue workers there.
Tributes have rushed in as families and friends attempt to come to terms with the news.
This was the first major aviation disaster in Western Europe in seven years. The plane had been grounded for repairs the day before the crash, though Lufthansa has denied that this could be related to the incident.
The White House has said there is no suspicion of terrorism.
VICE News' Melodie Bouchaud contributed to this report.
Follow Sally Hayden on Twitter: @sallyhayd
This story was originally published March 25 at 8:10am ET