South Korea has ordered an investigation into aviation safety after the country's worst accident killed 179 people

By Ju-min Park and Hongji Kim

MUAN REGION, South Korea (Reuters) – Acting South Korean President Choi Sang-mok on Monday ordered an emergency safety inspection of the country's entire airline operating system as investigators worked to identify the victims and determine what caused the country's deadliest air disaster.

All 175 passengers and four of six crew members were killed when a Boeing Jeju Air (NYSE: ) 737-800 landed on its belly and skidded off the end of the runway at Muan International Airport, exploding in a fireball when it hit a wall. Two crew members were pulled out alive.

The top priority now is to identify the victims, support their families and treat the two survivors, Choi said at a disaster management meeting in Seoul.

“Even before the final results are known, we ask the officials to transparently disclose the accident investigation process and inform the bereaved families immediately,” he said.

“Once the accident is rectified, the Ministry of Transport is requested to conduct an emergency safety review of the entire aircraft operation system to prevent the recurrence of air accidents,” he said.

The transport ministry said authorities were considering whether to carry out a special inspection of all 101 Boeing 737-800 aircraft operated by South Korean Airlines.

Jeju Air flight 7C2216, arriving from the Thai capital of Bangkok with 175 passengers and six crew on board, attempted to land at the airport in the south of the country shortly after 9am (0000 GMT) on Sunday.

Investigators are looking into bird strikes and weather conditions as possible factors in the crash, fire officials said. Experts say many questions remain, including why the plane, powered by two CFM 56-7B26 engines, appeared to be going so fast and why its landing gear did not appear to be down when it skidded off the runway and hit a wall.

CFM International is a joint venture between GE Aerospace and Frances Saffron (EPA:).

On Monday, Department of Transportation officials said that when the pilots made a scheduled approach, they told air traffic control that the plane had struck a bird, shortly after the control tower alerted them that birds had been spotted nearby.

The pilots then declared a Mayday and signaled their intention to go around shortly before the aircraft skidded down the runway in a belly landing and struck a structure at the end of the runway.

Officials are investigating what role the end of the runway at landing, including the embankment it was standing on, played in the crash, Department of Transportation officials said at a news conference.

The crash killed mostly local residents returning from a holiday in Thailand, and two Thai nationals also died.

On Monday morning, investigators were trying to identify some of the last remaining victims as grieving families waited in the Muan airport terminal.

Park Han-shin, who lost his brother in the accident, said authorities told him his brother had been identified but had not seen his body.

Park urged the families of other victims to come together in disaster response and recovery efforts, citing the 2014 ferry sinking that killed more than 300 people. The disaster was followed by a prolonged effort to identify the victims and the cause of the sinking.

Rescue workers were sifting through the wreckage, which was almost completely destroyed when the plane was engulfed in an explosion of flames and debris at a regional airport near the country's winding west coast.

Transportation Department officials said the jet's flight data recording had been recovered, but it appeared to have suffered some external damage and it was not yet clear whether the data was sufficiently intact to be analyzed.

Muan Airport remains closed until Wednesday, but the rest of the country's international and regional airports, including the main Incheon International Airport, were operating as scheduled.

Jeju Air shares hit a record low on Monday, trading as much as 15.7% lower.

Under global aviation rules, South Korea will lead a civilian investigation into the crash and automatically involve the National Transportation Safety Board (NTSB) in the United States, where the plane was designed and built.

The NTSB said it is leading a team of US investigators to assist South Korea's aviation authority. Boeing and the Federal Aviation Administration also participated.

Choi, who oversaw recovery efforts and investigations, became acting leader just three days ago after the country's president and prime minister were impeached over the imposition of short-term martial law.