Some passengers were pulled out of broken windows, and one man stood atop a carriage lying on its side, using a pickaxe to try to smash through a window.
Images showed one car pointing up into the air with one of its ends twisted and disfigured, and another severed in two.
Officials gave differing death tolls in the immediate aftermath of the crash just outside Santiago de Compostela, on the eve of the city's annual religious festival that attracts tens of thousands of Christian pilgrims from around the world.