A sequence of TRACE 1600 Å images with the SOHO/MDI magnetograms at 23:59:30 UT on Feb. 8 superimposed. The solid white and the black lines are the contours of the positive and the negative magnetic fields, respectively. The levels of the contours of the magnetic fields are ± 50 G, ± 100 G, and ± 300 G. The green lines denote the polarity inversion lines. Two blue arrows indicate the two flare ribbons.