In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.

• One of the pilots on board Germanwings Flight 9525 was locked out of the cockpit when the plane crashed, a senior military official told The New York Times Wednesday, citing evidence from the cockpit voice recorder. 
  
 • Lufthansa, the parent company of Germanwings, said "we have no information from the bodies investigating the incident that would corroborate the report in The New York Times. We will not participate in speculation, but we will follow up on the matter." 
  
 • Helicopters have airlifted some victims' remains from the site of the Germanwings plane crash in the French Alps, the Gendarmerie said Wednesday, according to CNN affiliate France 2. 
  
 Full story: 
  
 Investigators trying to determine what caused the crash of Germanwings Flight 9525 have made a startling discovery in an audio recording, according to a New York Times report : One of the plane's pilots was locked out of the cockpit before the crash. 
  
 "You can hear he is trying to smash the door down," a senior military official involved in the investigation told the newspaper, describing audio from the cockpit voice recorder, one of the plane's black boxes. 
  
 "We don't know yet the reason why one of the guys went out," the official said, according to the Times' report. "But what is sure is that at the very end of the flight, the other pilot is alone and does not open the door." 
  
 Lufthansa, the parent company of Germanwings, said it was looking into the report. 
  
 "We have no information from the bodies investigating the incident that would corroborate the report in the New York Times," spokesman Boris Ogursky said. "We will not participate in speculation, but we will follow up on the matter." 
  
 The Times' report is a "terribly shocking revelation," CNN aviation analyst Peter Goelz said. But he and other experts cautioned that it's still unclear what could have been going on inside the cockpit. 
  
 Possibilities range from a medical emergency to something more nefarious, like a suicide mission, CNN aviation analysts said. 
  
 Officials previously said that hadn't ruled out terrorism, but it seems unlikely. 
  
 French authorities revealed earlier Wednesday that they'd been able to access audio from the recorder, even though its external casing was damaged. 
  
 But they disclosed few details about what the recording actually contained, saying only that there was one audio channel with voices on it that went all the way up to the time of the crash. 
  
 "It is too early to draw conclusions to what happened," said Remi Jouty, head of the BEA, the French aviation investigative arm leading the probe. "There is going to be detailed work performed on that audio file to understand and interpret the sounds and the voices that can be heard." 
  
 Finding the plane's second black box will also be critical to understanding the mystery of what went on inside the jet. 
  
 That box, the flight data recorder, hasn't been found yet, but Lufthansa CEO Carsten Spohr said Wednesday that there's a high probability it will be. 
  
 The mountainous terrain where the Germanwings jet went down is difficult to access. 
  
 Investigators scoured dangerous terrain in the French Alps as they searched for clues in the wreckage. 
  
 Workers dropped to the crash site from helicopters, Jouty said, and had to be tied together because the steep area in the mountains is so treacherous. 
  
 'We need to understand what happened' 
  
 Spohr said Tuesday's plane crash "represents the darkest hours" in the history of his company, which owns Germanwings. 
  
 Officials are struggling to understand how an airplane that "was in perfect technical condition" with two experienced pilots "was involved in such a terrible accident," he said. 
  
 But even worse, he said, is seeing the heartbreak of the relatives and friends of the victims who perished in the crash. 
  
 "What they have gone through is, of course, incomprehensible," he said, describing what he said was an emotional meeting between the relatives and airline executives Wednesday. 
  
 And now, he said, the company's focus will be taking care of them. 
  
 Special Lufthansa flights will take relatives and friends of victims to southern France on Thursday, so they can be near the search scene, he said. 
  
 "We need to understand what happened," French President Francois Hollande said. "We owe that to the families." 
  
 Victims from 18 countries 
  
 The doomed flight was traveling from Barcelona, Spain, to Dusseldorf, Germany, when it crashed Tuesday in the French Alps. 
  
 Germanwings said the plane reached its cruising altitude of 38,000 feet, and then dropped for about eight minutes. The plane lost contact with French radar at a height of about 6,000 feet. Then it crashed. 
  
 Teams have begun the daunting task of identifying the victims' bodies, but caution that it could take time to complete. 
  
 Clues in the debris 
  
 Investigators are still trying to piece together what caused the crash. 
  
 Jouty, the head of the investigation team, said the debris suggests the plane hit the ground and then broke apart, instead of exploding in flight. 
  
 Radar followed the plane "virtually to the point of impact" in the Alps in southern France, Jouty said. The flight's last altitude recorded by radar was just over 6,000 feet. 
  
 FBI agents based in France, Germany and Spain are looking through intelligence sources and cross referencing the passenger manifest of Germanwings Flight 9525, two senior law enforcement officials said. So far, their search hasn't turned up anything that "stands out" or anything linking the passengers to criminal activity, according to one official. ||||| One of the main questions is why the pilots did not communicate with air traffic controllers as the plane began its unusual descent, which suggested that the pilots or the plane’s automated systems may have been trying to maintain control of the aircraft as it lost altitude. 
  
 Among the theories that have been put forward by air safety analysts not involved in the investigation is the possibility that a pilot was incapacitated by a sudden event such as a fire or a drop in cabin pressure. 
  
 A senior French official involved in the investigation, who spoke on the condition of anonymity, said that the lack of communication from the pilots during the plane’s descent was disturbing, and that the possibility that their silence was deliberate could not be ruled out. 
  
 “I don’t like it,” said the French official, who cautioned that his initial analysis was based on the very limited information currently available. “To me, it seems very weird: this very long descent at normal speed without any communications, though the weather was absolutely clear.” 
  
 Image The French aviation authorities have recovered an audio file from the cockpit voice recorder, but did not say whether it was partial or complete. Credit Bureau d'Enquetes et d'Analyses, via Associated Press 
  
 “So far, we don’t have any evidence that points clearly to a technical explanation,” the official said. “So we have to consider the possibility of deliberate human responsibility.” 
  
 Mr. Jouty said it was far too early in the investigation to speculate about possible causes. 
  
 “At this moment, I have no beginning of a scenario,” Mr. Jouty said. However, he said there was not yet any evidence available that would support a theory of a depressurization or of a midair explosion. 
  
 Speaking on the French radio station RTL, Interior Minister Bernard Cazeneuve said Wednesday morning that terrorism was not a likely “hypothesis at the moment,” but that no theories had been excluded. He said the size of the area over which debris was scattered suggested that the aircraft had not exploded in the air but rather had disintegrated on impact. 
  
 Lufthansa, the parent company of Germanwings, has characterized the crash as an accident. The airline has not disclosed the identities of the pilots, except to say that the captain was a 10-year veteran with more than 6,000 hours of flying time in A320s. 
  
 Image French emergency services resumed work on Wednesday near the crash site of a Germanwings jet. Credit Peter Kneffel/European Pressphoto Agency 
  
 The French Bureau of Investigations and Analyses, which is leading the technical inquiry into the crash, sent seven investigators to the crash site Tuesday. They have been joined by their counterparts from Germany, as well as by technical advisers from Airbus and CFM International, the manufacturer of the plane’s engines. 
  
 Speaking on Europe 1 radio, Jean-Paul Troadec, a former director of the French air accident investigation bureau, said one of the big challenges for investigators would be to protect the debris at the crash site from inadvertent damage. 
  
 “We need to ensure that all the evidence is well preserved,” Mr. Troadec said, referring to the pieces of the plane littered across the steep slopes as well as to the remains of the victims. The identification of the victims will probably require matching DNA from the remains with samples from relatives. 
  
 The recovery effort will be a laborious task, given the state of the wreckage, the difficult terrain and the fact that the crash site is so remote that it can be reached only by helicopter. 
  
 Cabin depressurization, one of the possibilities speculated about on Wednesday, has occurred before, perhaps most notably in the crash of a Cypriot passenger plane in 2005 that killed all 121 people on board as it approached Athens. In that case, Helios Airways Flight 522, a slow loss of pressure rendered both pilots and all the passengers on the Boeing 737 jet unconscious for more than three-quarters of an hour before the aircraft ran out of fuel and slammed into a wooded gorge near Athens, the Greek capital. 
  
 Investigators eventually determined that the primary cause of that crash was a series of human errors, including deficient maintenance checks on the ground and a failure by the pilots to heed emergency warning signals. |||||
A seemingly dramatic turn in the investigation of the Germanwings plane crash: Audio reveals that one pilot was locked out of the cockpit before the plane went down and tried desperately to get back inside, reports the New York Times. The other pilot never opened the door, for reasons that remain unclear. “The guy outside is knocking lightly on the door and there is no answer,” a crash investigator tells the Times. “And then he hits the door stronger and no answer. There is never an answer.” He adds, “You can hear he is trying to smash the door down.” It's not clear whether the pilot in the cockpit was incapacitated, but he was alone in there when the plane crashed. Nor is it clear why the second pilot left the cockpit in the first place. One thing that is clear is that the pilot never sent a distress call during the plane's eight-minute descent. Meanwhile, helicopters today began airlifting the remains of passengers from the crash site in the French Alps, reports CNN. In the latest update, three Americans were among the dead, including a mother and daughter from Virginia.