Flowers and a message of condolence laid by people working at the site where an aircraft went off the runway and crashed, are pictured at Muan International Airport in Muan, South Korea [Source: Reuters]

South Korea’s acting President Choi Sang-mok ordered an emergency safety inspection of the country’s entire airline operation as investigators worked to identify victims and find out what caused the deadliest air disaster on South Korean soil.

All 175 passengers and four of the six crew were killed when a Jeju Air (089590.KS), opens new tab Boeing (BA.N), opens new tab 737-800 belly-landed and skidded off the end of the runway at Muan International Airport, erupting in a fireball as it slammed into a wall. Two crew members were pulled out alive.

The top priority for now is identifying the victims, supporting their families and treating the two survivors, Choi told a disaster management meeting in Seoul.

As a first step, the transport ministry announced plans to conduct a special inspection of all 101 Boeing 737-800 aircraft operated by South Korean airliners beginning on Monday, focusing on the maintenance record of key components.

The 737-800 is one of the world’s most flown aircraft with a generally strong safety record. It was developed well before the MAX variant involved in a recent Boeing safety crisis.

Jeju Air flight 7C2216, arriving from the Thai capital Bangkok, was trying to land shortly after 9 a.m. (0000 GMT) on Sunday at the airport in the south of the country.

Investigators are examining bird strikes, whether any of the aircraft’s control systems were disabled, and the apparent rush by the pilots to attempt a landing soon after declaring an emergency as possible factors in the crash, fire and transportation officials have said.

Experts say many questions remain, including why the plane, powered by two CFM 56-7B26 engines, appeared to be travelling so fast and why its landing gear did not appear to be down when it skidded down the runway and into a concrete embankment.

CFM International is a joint venture between GE Aerospace (GE.N), opens new tab and France’s Safran (SAF.PA), opens new tab.

On Monday, transport ministry officials said that as the pilots made a scheduled approach they told air traffic control the aircraft had suffered a bird strike, shortly after the control tower gave them a warning birds were spotted in the vicinity.

The pilots then issued a Mayday warning and signalled their intention to abandon the landing and to go around and try again. Shortly afterwards, the aircraft came down on the runway in a belly landing, touching down about 1,200 metres (1,310 yards) along the 2,800 metre (3,062 yard) runway and sliding into the embankment at the end of the landing strip.