A dead stowaway was on Monday, April 17, discovered in the wheel well of a KLM Royal Dutch Airlines Boeing 777.

The aircraft (registered PH-BQM) flew from Nigeria’s commercial hub, Lagos, according to Belgium’s Aviation24.

It’s unclear how the undocumented passenger found his way into the aircraft but an investigation has been launched to determine the circumstances surrounding the incident.

According to a statement issued by the airline, the dead stowaway was discovered after the plane had landed.

The extra passenger is believed to have died from hypothermia.

Occasionally, stowaways are discovered in wheel wells of aircraft.

“Sometimes they survive, but most of the time it goes wrong given the sharp drop in temperature. On longer flights, temperatures can go down to minus fifty degrees, impossible to survive,” a spokesperson of the Royal Dutch Marechaussee explained.