You are walking down the school hallway until you saw some students acting strange.. you walked towards them and noticed that they were trembling and spitting blood out.. when you looked out of the window you saw the city burning, you ran back to your class 1-A, you explained what you saw and that the city was burning down

Aizawa: “alright stay here and work together, I will inform the other pro heroes. I will be back Later”

Izuku: “what is happening???”