When this father feels guilty, he asks Reddit:
I (41M) have two daughters with my wife (38F). I have a 10 y/o, 'Carol' & a 7 y/o, 'Jane'.
I was at the playground with my children whilst my wife was shopping. I was sitting on a park bench by the playground.
I heard an argument between the two girls & said 'what's going on?' My 7 year old, yelled 'that's not fair!' & began running towards me shouting 'daaaad'.
Jane was doing a kind of fake, frustrated cry where her face was scrunched up, but no tears were coming out. As her eyes were closed she didnt see the edge of the playground barrier (wooden fence almost about 4 inches high to keep the bark in).
She tripped and landed hard on the concrete path. She didnt put her arm out in time & (I found out later) she had a clean break through both her radius & ulna.