TAIPEI (Taiwan News) — The bodies of two Taiwanese tourists and a pilot were spotted inside a volcanic crater in southwest Japan on Wednesday, per UDN.

They were discovered nearly a month after their sightseeing helicopter crashed on Mount Aso. Drone footage revealed the three bodies near the wreckage inside Kumamoto Prefecture‘s Nakadake No. 1 crater.

The passengers were said by CNA to be a 36-year-old Taiwanese woman, a 41-year-old Taiwanese man, and a 64-year-old male pilot.

Forced landings or crashes of aircraft or helicopters inside volcanic craters are rare. Japanese firefighters and National Accident Investigators said the rescue mission was “full of unknowns” and “unlike any accident we have encountered.” 

Police and fire officials said extreme volcanic gases and temperatures up to 80 C had ruled out manned recovery operations. The families of the Taiwanese passengers reportedly agreed to suspend high-risk rescue efforts.  

The helicopter took off at 10:50 a.m. on Jan. 20 from an Aso City tourist facility for a planned 10-minute flight and lost contact shortly after 11 a.m.