It almost worked

Mia Quinn is 10 when she decides she wants to die. Running away from her abusive household and onto the ledge of a tall building.

Natasha Romanoff had only meant to go on a walk and scale the tall buildings of the city. It made her feel more alive than life was currently willing to give.

Fate intervened that day, if Natasha had made it on top of that building a mere few seconds later then Mia Quinn wouldn't exist any more...it's not like anyone would have noticed anyway.