>> a flight attendant empties a fire extinguisher, trying to control the smoke, but they can't find the source of the fire. >> when they open the lavatory door, they see smoke but no open flame. that was behind the walls in an inaccessible areas. >> a fire behind the wall is thç worst-case scenario. it's almost impossible to put out or contain. a disaster is in progress. >> the smoke was clearing and then all of a sudden i lost all my electric power. >> that's when the crew realized they had a life-threatening event on their hands. they needed a crew on the ground as soon as they could get there. >> mayday. we're going down. >> moments later, dense smoke begins to come through the cabin walls. >> roger. do you have time to give me the nature of the emergency? >> we have a fire in the wash -- back wash room and filling up with smoke right now. >> filled the cabin very quickly.