171 Å images taken by TRACE. a) The arrow indicates the EUV channel corresponding to the filament involved in the eruption. b) Early phase of the eruption, when a highly twisted arcade becomes visible. The box shows a zoom on the western side of the arcade and the arrow indicates a crossing of type II. b) Main phase of the eruption. The box shows a zoom on the eastern side of the arcade and the arrow indicates a crossing of type III. The field of view is ~280 × 280 Mm². North is at the top and west to the right.