On Tuesday, March 25, 2015, a Germanwings plane traveling from Madrid, Spain, crashed in the French Alps, killing 144 passengers and five crewmembers. The plane was flying along steadily when suddenly, the plane began descending. No distress call was made.

According to Cnn.com, investigators discovered a recording of what happened in the cockpit right before the deadly crash. The voice recording reveals that co-pilot Andreas Lubitz deliberately crashed the plane. The pilot, Captain Patrick Sondenheimer left the cockpit to go to the bathroom a few minutes before the two pilots were supposed to begin their descent toward the airport. But co-pilot Lubitz had other ideas.

The recording proves that when Captain Sondenheimer came back from the bathroom, the cockpit door was closed and locked. Captain Sondenheimer entered the password to open the door, but Lubitz overrode it. The recording clearly has Captain Sondenheimer first knocking on the door, then pounding persistently. He screams, “For God’s sake, open the door!” while attempting to break down the sealed door.

A few minutes later, the sound of metal banging together, most likely more attempts to break down the door, can be heard along with the screaming of passengers. The plane was losing altitude rapidly. Air traffic control attempted to contact the plane, but they received no reply. The plane alarm sounds at 6500 feet, warning the cockpit that they are approaching terrain.

Shortly before the crash, investigators report that they can hear the wings scraping the sides of the mountain. Seconds before the crash, you can still hear Captain Sondenheimer pleading with Lubitz and passengers screaming.

After the recording was analyzed, investigators discovered that Lubitz had severe depression and was not supposed to be flying. Investigators found a ripped note in Lubitz’s trash can from his doctor excusing him from work—dated the day of the crash.

There is also a medical record of Lubitz having various mental issues. Lubitz’s mental problems were psychosomatic, which means they are caused by a stress or internal conflict. In addition to his severe mental problems, he also went to a doctor because he was having trouble seeing. This is said to be the nature of the note excusing him from work. When confronted with the startling piece of evidence, the airlines claimed this record was far before Lubitz earned his pilots license.

The airline was, however, aware that Lubitz was suffering from depression and still hired him and allowed him to fly.