Endeavor was chasing some villains in a rural area and caught them. But was careless and burned down a house of an innocent family. The man and woman inside were too late to get out and died.

Endeavor is gone by now but Eraserhead/ Aizawa was assigned to the scene. He’s still here.

As some firefighters are trying to control the fire, Aizawa’s standing on the side, talking to Detective Tsukauchi, when he hears a loud, terrified, scream. Of a kid. (You)