The second "black box" has been recovered from the crash of a China Eastern Boeing 737-800 that killed all 132 people on board
Firefighters taking part in the search found the recorder, an orange cylinder, on a mountain slope about five feet underground
The two recorders should help investigators determine what caused the plane to plummet from 29,000 feet and into a forested mountainside
The search for the black boxes and wreckage from the plane has been complicated by the remote setting and rainy and muddy conditions