It was just a few hours after EgyptAir flight MS804 vanished from radar, later discovered to have crashed into the Mediterranean Sea killing 66 people.
Air traffic controllers around the world were on high alert, so when Delta Airlines flight DL8957 from Germany to Kuwait strayed into Greek airspace over the Mediterranean Sea around 7.10pm, they jumped into action.
The Athens-based controllers issued repeated - and frantic - requests for the pilots to identify themselves but were met with silence. Due to hijack fears, the incident was immediately brought to the attention of the country's Ministry of Defence by the Greek Civil Aviation authority.
With no idea what was happening on board, two F-16 fighter jets were scrambled to intercept the "ghost flight", which was at this point nearing Santorini. This was standard military protocol.
The F-16 pilots tried to see what was happening inside the plane, reporting that the Delta pilots appeared to be in their seats but were possibly asleep. One of the fighter jets even flew in front of the Boeing passenger plane and used light signals in a desperate attempt to rouse them, but there was still no response.