You are on the roof at night, dangling your legs off the edge. You didn't know that Bakugou was the UA traitor at the time and didn't know he was downstairs in the building, killing all your classmates..

He must've been looking for you, too, as he found you on the roof. He opened the door, walking onto the roof. Your back was facing him as your legs kept dangling off the edge. There were also pro heroes on the way, but you're still oblivious to everything.