riverside of donau

At 20:00, I was on the riverside of Donau, or Danube, the great and longest river in EU. Its surface was totally frozen and on it, there was about 2cm-snow-layer. It was just 2cm and the ice itself was so thin that I could break it easily by throwing only a small snow-chunk.
Inside the ice, the river looked deep and dark. In that darkness, fishes seemed to be too reluctant to move.
I came here by taking subway. When walking on the snow road to the shore of Donau, I saw several juveniles skateboarding on the dry, no-snow place under a bridge. They played skateboards without saying anything. Just a strange feeling. On one hand, I saw the frozen Donau silently running under the thin ice. On the other, I heard only sharp noises occurred sometime by juveniles' boards hitting the concretes.
Walking back to the bridge, I saw that there was a multiplex, or movie theater complex, which at that time had Luc Besson's "The Messenger: The Story of Joan of Arc", I remember, because of its huge poster in front of the building.
The juveniles might be just waiting for the movie while playing here, or might not.
Here was near the great Donau, Wien, Austria.