marylou retton breaking her silence to hoda kotb. why she's grateful to be here after a life-threatening illness. >> announcer: this is "nc nightly news with kate snow". the nightmare stereo in the sky, you've probably seen it now, part of a boeing 737's cabin blown open in flight. the near disaster on friday sending shock waves through the aviation industry worldwide. this is the scene minutes after takeoff from portland, oregon, passengers describing how the opening sucked out loose items from the cabin. thankfully no one was seriously injured. the national transportation safety board was on the ground today trying to determine what caused this to happen. the faa chief announcing that nearly 200 other similar planes in the u.s. will remain grounded as they search for answers, and aviation agencies across the world now are doing the same. tom costello leads us off