Eruption event on April 25, as seen by SOHO/LASCO-C2 on the right, and STEREO-A/COR2 on the left in almost simultaneous frames and in reverse colors. Note that the event is moving eastward in SOHO/LASCO-C2 frame and westward in STEREO-A/COR2. These frames were used to estimate the structure direction using triangulation, with the fork shape indicated by the black arrow as the leading point.