Air crash investigators found evidence of a bird strike on a commercial jet that crashed in South Korea, killing 179 people on board. A preliminary report released by authorities Monday stated that both engines on the Jeju Air Boeing 737-800 jet contained duck DNA, specifically that of Baikal teals—a migratory bird that breeds in Russia and flies to East Asia for winter. However, the six-page report made no firm conclusion as to the cause of the crash at Muan International Airport on Dec. 29. The plane’s flight data recorders stopped working four minutes before the aircraft skidded off the runway during an emergency belly landing without its landing gear deployed. “After the crash into the embankment, fire and a partial explosion occurred. Both engines were buried in the embankment’s soil mound, and the fore fuselage scattered up to 30-200 meters from the embankment,” the report said. The crash was the deadliest air disaster ever to take place on South Korean soil.