I'm underground in a well-lit train station. The ceiling is arched down to the floor with patterned gray stone, and the floor is bright white, almost like marble, but somehow not as hard. The floor glows with reflected light. One of my closest friends is in a wheelchair from some temporary injury, and I'm pushing him around trying to get the train. He's really upset about the injury and I tell him it'll be okay.
In order to get to the train, we have to cross over a moat full of murky water. The bridge is quickly darting back and forth, like one of the platforms from Super Mario Bros. We get on the platform okay, but getting off is too hard because it's moving so fast. He falls out of the wheelchair sideways and into the water!
He goes under right away and I can't get him out. I can't even see him. He pops up pretty soon, but it's too late. He fell apart in the water or something tore him apart and you can see his spine. He's limp and freezing and flops around like a rag doll. I don't know what happened or why he died or what to do and I'm weeping and then I wake up.