SEOUL, South Korea (AP) — South Korea will remove a concrete structure at an airport runway that may have been involved in a devastating plane crash that killed all but two of the 181 people on board last month.

Some experts and observers have said Muan International Airport’s localizer — a concrete fence at the end of the runway that houses a set of antennas designed to guide aircraft safely during landings — likely made the crash of the Jeju Air plane worse, though the incident is still under investigation.

The Boeing 737-800 skidded off the airport’s runaway on Dec. 29 after its landing gear failed to deploy, slamming into the concrete structure and bursting into flames. Many observers said the structure should have been made with lighter materials that could break more easily upon impact.

The Transport Ministry said Wednesday it will remove the structure at Muan airport and install a new one made of easily breakable materials.

It said it will push to remove or make adjustments at similar facilities at six airports across South Korea.

The black boxes of the Boeing jetliner stopped recording about four minutes before the accident, South Korean officials said, possibly complicating investigations into the cause of the disaster.

Investigators have said that air traffic controllers warned the pilot about possible bird strikes two minutes before the aircraft issued a distress signal confirming that a bird strike had occurred, after which the pilot attempted an emergency landing.