[That's the issue, Izuku isn't sure about the full details of the entire situation either. Izuku had arrived only to see Katsuki's hurt body laying on the ground. He remembers the way it made the sound in his ears ring and his heart feel like it was going to beat in overdrive.]

I was trying my best ... But I...

[He can't help but feel like it's his fault. If he was only faster. If only he had been there beside Katsuki instead of behind him.]

Kacchan, I'm not sure what happened for sure before I woke up here on that train but I ... I'm sorry.