Flight 370
You may remember the case of Malaysia Airlines Flight 370. On the 8th of March 2014, this international passenger flight, a Boeing 777-200ER registered as 9M-MRO, vanished from the face of the Earth to never be seen again.
The plane was flying from the Kuala Lumpur International Airport in Malaysia to Beijing. But just 38 minutes after taking off, while the aircraft was over the South China Sea, it disappeared.