Authorities in the Southeast Asian nation of the Philippines announced Thursday that all four occupants of a small plane that crashed there over the weekend had been confirmed dead. This comes after a perilous search operation atop a volatile volcano. According to CNN affiliate CNN Philippines, who cited Camalig Mayor Carlos Irwin Baldo, the bodies of the pilot Rufino James Crisostomo Jr., crew member Joel Martin, and Australian technical consultants Simon Chipperfield and Karthi Santhanam have been discovered on Mount Mayon volcano. A team is working to retrieve them. According to Richard Tantoco, president and chief operating officer of Energy Development Corp., a geothermal company with offices in Manila, all four men were employees of the company. https://youtu.be/TvGZ7BXLNqQ According to the Civil Aviation Authority of the Philippines, the six-seater Cessna 340 aircraft was headed for Manila when it lost communication with air traffic control on Saturday after taking off from Bicol International Airport in Albay province (CAAP). On Sunday, the debris was discovered at a height of roughly 6,000 feet (1,823 meters). A "moderate" level of volcanic disturbance, rainy circumstances, and the possibility of landslides hindered search efforts, according to CAAP. The crash is still under investigation, according to CAAP.