What unique coincidence along your family's line led to your existence?

Example:
My mother worked in her Aunt’s cafe/Bakery in a small Town in northern Manitoba, Canada.

My father traveled through this Town one day and stopped in for a quick bite to eat.

He met my mother, they dated, married,had five children and lived a long life.

It was coincidence that they met this way as he never before had traveled so far from his home city .

I would not exist had he not gone there that day.
Please no jokes or crude remarks in your answers.