You are Izuku's big brother/sister

Izuku is one year old he can't talk yet, he wasn't really your brother, your parents adopted him, you never loved him or cared for him, one day, your parents were at work, Izuku was playing with a doll and crawling on the floor like any baby do, he got out of his room because the door was open, he headed towards the stairs, he tried to go down but he fell, and hurt his foot, which made him cry, you were in your room when you heard him crying, what would you do?