Flight recorders from the passenger jet that crashed in South Korea last month, killing more than 170 people, stopped working minutes before the plane belly-landed and exploded on the runway, investigators said Saturday.

The voice and data recorders pulled from the wreckage of the Jeju Air Co. jet in South Korea failed to capture the final moments before the Boeing Co. 737-800 made an emergency landing and crashed, depriving investigators of evidence to help understand the cause of the country’s deadliest aviation accident.

Officials say the black boxes of a Boeing jetliner that crashed in South Korea last month stopped recording about four minutes before the accident.