ขณะที่ข้าพเจ้ากำลังเดินลงบันไดของรถ

While I'm walking down the stairs of the subway have seen students who're just tamue chat, while downstairs is identical. So he has not seen his front is the old woman trying to walk down a gradual stair railing island.

While I was walking down the stairs of the subway. One student was seen chatting on mobile while coming down the stairs as well. As a result, he does not look that old women in front of him then slowly walked down the staircase rail. Students that crashed into the elderly woman was injured.

While I was walking down the stairs of the metro. See a student chat mobile while down the stairs. Therefore, he didn't think his front is old lady's Island railing gradually walk down.