Germanwings crash: 1 Pilot locked out of plane's cockpit

Evidence from a cockpit voice recorder recovered from the Germanwings flight 4U9525 that crashed on Tuesday suggests that one pilot left the cockpit before the plane’s descent and was unable to get back in, according to two separate reports.

French air accident investigators say they have extracted a recording that contains “voices and sounds” from the cockpit of the plane before it crashed in the Alps, killing all 150 people on board.
A senior military official involved in the investigation told the New York Times that there was a “very smooth, very cool” conversation between the two pilots during the early part of the flight from Barcelona to Düsseldorf.
Later in the recording, the audio suggests that one of the pilots left the cockpit and could not re-enter. The audio gives no indication of the condition of the pilot who remained in the cockpit.

“The guy outside is knocking lightly on the door and there is no answer,” the investigator, who asked to remain anonymous, told the New York 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.”
“We don’t know yet the reason why one of the guys went out,” said the official, who requested anonymity because the investigation is continuing.
“But what is sure is that at the very end of the flight, the other pilot is alone and does not open the door.”