South Korean President Lee Jae Myung on Monday apologised to the families of the 179 people who died in a Jeju Air crash a year ago, vowing to reveal the truth behind the worst aircraft accident on the country’s soil.

Relatives of the victims held a tearful memorial service at Muan International Airport to mark the anniversary. They were overcome with sorrow and frustration because, a year on from the crash, little has come to light to explain what happened.

Kim Yu-jin, a representative of the families, said the government has wasted time by focusing on cleaning up the crash’s aftermath rather than finding out why it happened.

“We will not stop until the truth is finally revealed and those responsible are held accountable so that the lives of the 179 were not lost for nothing,” she said at the service, which was attended by families, the Parliament’s speaker and other government officials.

The families have demanded answers about the accident, after investigators delayed releasing a report on what went wrong on December 29, 2024, when the Jeju Air jet crash-landed and slammed into an embankment at the end of the runway.

It erupted in a ball of flames, killing all but two of the 181 people on board. The government-led Aviation and Railway Accident Investigation Board said in a preliminary report in January that both of the plane’s engines sustained bird strikes.

But questions remain about safety lapses, the design of the runway at Muan International Airport where the crash occurred and what actions the pilots took in the last few minutes of the flight.

President Lee, who has prioritised public and job safety since taking office in June, said it was his duty to make sure tragedies like the Jeju Air crash do not happen again.

“As president who has the responsibility to protect the lives and safety of the people, I offer my deepest apologies,” Lee said in a message released on Monday.

“The disaster clearly revealed the systematic problems and limitations of our society,” Lee said. “What’s needed now is not perfunctory promises or empty words but rather real change and action.”

Parliament has been reviewing a plan to overhaul the aircraft accident investigation board to ensure independence and greater expertise.

Some family members have said investigators appeared to blame pilot error rather than exploring other factors including the embankment at the end of the runway that likely made the crash more deadly.

In July, investigators said the left engine, which sustained less damage than the right one following bird strikes, was shut down before the crash landing.

Few other details have emerged from the investigation, which had been hampered because the flight data recorder and cockpit voice recorder both stopped recording in the final seconds of the flight.

Experts say most air accidents are caused by multiple factors and they cautioned against putting too much weight on incomplete evidence.