Germanwings Flight 9525

On March 24, 2015, Germanwings Flight 9525

took off from Barcelona. It never reached Düsseldorf.

Roughly halfway through the journey, the captain stepped out of the cockpit for a bathroom break. That's when co-pilot Andreas Lubitz locked the door behind him—and never let anyone back in.

With the autopilot quietly set to descend to just 100 feet, the Airbus A320 began its fatal drop.

The captain shouted and pounded on the door.

Air traffic controllers tried to get through.

Nothing. Lubitz didn't say a word.

Inside the cabin, passengers screamed in the final seconds. The plane slammed into a mountainside in the French Alps at 430 miles per hour. No one survived.

Lubitz, who had been declared unfit to fly by a doctor, had hidden his condition from his airline. After the crash, a former girlfriend said he once told her: "One day I'll do something that will make everyone remember my name."

That day was March 24.