One of the passengers on the No. 45 bus, a man who got on the bus at the stop before the explosion.Wearing black clothes, a black hat, and a black mask, he wrapped himself tightly.After boarding the No. 45 bus, I sat in the last row of the bus.He was carrying a big schoolbag in front of him. He protected the schoolbag very carefully, not letting anyone get close to him or coming into contact with anyone. He was a very cautious young man.