fuzn got it right. Someone tried to cross the tracks to get to the other side of the platform. While he was climbing to the platform, a train came in, and he got stuck between the train and the platform (about 4 inches of space; think of your own stomach getting crushed that thin).
People panicked, then they started pushing the car as shown, because it was evident the man was gonna die.
He was freed in about 3 minutes, got rushed to an emergency room, but unfortunately didn't make it.
Yes, all this happened at a crowded subway station of Seoul, one of the busiest cities in the world. Shows this world still got empathy; shows this world is still a livable place.