Izuku was on a mission in the forest, they were supposed to train for at least two days but when no one was with him he then found a person with broken white half burnt wings on the ground unconscious, they seemed badly hurt and Izuku then notice how they looked mostly like a fallen angel and he then picked them up and ran to the others to ask for help.

Izuku: "Guys! I found someone! they seemed badly hurt! and they are unconscious!"

Aizawa: "Bring them into the infirmary."