Missing engine cover prompts Delta flight's emergency landing

(CNN)Experiencing a little turbulence is pretty common for frequent fliers.

Looking out the window and seeing the plane's innards on display? Not so much.
Passengers aboard Delta Air Lines Flight 762 from Atlanta to Chicago got a little more than sloshed drinks when the cabin lights came on at 28,000 feet Sunday afternoon.
Those with a window seat got quite the view: The piece covering the plane's right engine -- or cowling, as it's called -- had come off.
    As photos posted by CNN affiliate WTVF showed, the loose piece then appeared to have struck part of the fuselage.
    The pilot declared an emergency, and the plane landed safely in Nashville.
    The 109 passengers aboard the Boeing 717 walked away uninjured, but with quite a tale to tell.
    Delta said it's been in touch with passengers with "a gesture of apology." And it's investigating exactly what went wrong.