Continental Flight 128 en route from Rio de Janeiro to Houston struck sudden turbulence over the Atlantic, plunged and shook violently, hurling passengers over seat backs and slamming them against luggage bins. At least 26 were hurt, four seriously.
The Boeing 767 made an emergency landing in Miami so the injured could be treated.
Unexpected turbulence is why pilots often tell passengers to keep their buckles fastened even if the "seat belt" sign is off and the skies are clear.
"It was just so sudden you didn't really have time to react," said passenger Carolina Portella, 18. "I grabbed the hand of the person next to me and just held on."
Flight attendants were thrown against the ceiling. Passengers who weren't belted in went flying into the overhead compartments; one woman hit a luggage bin so hard that her head stuck. Oxygen masks dropped. A child smacked his chest on a tray table and started bleeding.
"One lady, she just came out of her seat and flew over the middle row, hit her head on the wall and landed on her back," said passenger Diego Saavedra, 13, whose nose was bandaged as he spoke with reporters in the terminal of Miami International Airport.
Passengers said the terror lasted only a few seconds. A doctor sitting in first class tended to the injured until the plane diverted to Miami.