Authorities in Japan found a dead body in the landing gear of a Delta Air Lines flight that arrived in Tokyo on Sunday. The body was a man of dark complexion wearing only blue jeans and a red and blue long-sleeved shirt. There was no passport or personal belongings with him, and Japanese officials are seeking help from the US to identify the man.

The man’s body was found by a mechanic on the Boeing 777 Flight 59 that took off from New York. The plane had been towed to a freight area after the passengers got off at the gate. The maintenance worker found him inside the landing gear storage compartment door.

Police at the airport said the body showed no external injuries, but they could see signs of frostbite, which they think could have happened while the plane was flying. Narita Airport police spokesman Yoshimi Ichihara said that doctors believe he froze to death and suffered a lack of oxygen due to the altitude, which was at over 30,000 feet – the cause of death hasn’t been officially confirmed though. He added that if the man had any belongings with him, they probably fell out when the landing gear opened over the ocean.

A person has enough space to hide in the main housing compartment for the landing gear. However, the area is pressurized with the reset of the aircraft. Due to this, there have been many cases where stowaways have hidden there, but died because of freezing temperatures and lack of oxygen.