After analyzing the devices, the U.S. National Transportation Safety Board concluded​ that both the flight data and cockpit voice recorders stopped working about four minutes before the crash.

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 two black boxes on the Boeing jet involved in the worst aviation disaster on South Korean soil stopped recording about four minutes before the accident, the transport ministry said on Saturday. So