[It was far worse than he had imagined. Souji's mind works in rapid succession, making the connection.]

I remember hearing the cries from the leading caravan the second day into our trip, but we weren't affected ourselves... [No one should see others die like that, without power to stop them. He idly forms one of his hands into a fist.] Kanji...I'm sorry it had to happen to you and everyone else.

No one deserves that.

[And heavily implied that he should have stayed behind on his behalf and suffered in his stead.]