The co-pilot of Germanwings Flight 9525 deliberately crashed the aircraft in a mass murder–suicide in the French Alps, killing all 150 people on board.

Germanwings Flight 9525 was a scheduled international passenger flight from Barcelona–El Prat Airport in Spain to Düsseldorf Airport in Germany. The flight was operated by Germanwings, a low-cost carrier owned by the German airline Lufthansa. On 24 March 2015, the Airbus A320-211 operating the flight crashed 100 km north-west of Nice in the French Alps, killing all 150 people on board.

A murder–suicide is an act where an individual intentionally kills one or more people before or while also killing themselves. The combination of murder and suicide can take various forms:

• Suicide after or during murder inflicted on others
  • Suicide after murder to escape criminal punishment(s)
  • Suicide after murder as a form of self-punishment due to guilt
• Murder that entails suicide, such as suicide bombing
  • Suicide by pilot, or the deliberate crash of a vehicle carrying the perpetrator and others
• Murder of an officer or bystander during the act of suicide by cop
• Suicide before or after murder by proxy
• Murder linked with a person with suicidal ideation
  • Joint suicide in the form of killing the other with consent, and then killing oneself

The French Alps are the portions of the Alps mountain range that stand within France, located in the Auvergne-Rhône-Alpes and Provence-Alpes-Côte d'Azur regions. While some of the ranges of the French Alps are entirely in France, others, such as the Mont Blanc massif, are shared with Switzerland and Italy.