South Korea’s leading low-cost carrier, heavy with debt and its stock already near record lows, is now facing intense public and government scrutiny.

The discovery of the missing data suggests all power may have been cut, which is rare, a former government accident investigator said.

The two flight recorders on board a South Korean airliner stopped working before the jet crashed during an emergency landing and subsequent crash that killed 179 of the 181 people on board, officials said Saturday.