Three bruised/blackened nails

I discovered that my children and I each has a blackened nail from mishaps over the past month.
My son got his finger caught between two rounds of wood when chopping firewood. One of my daughter's students accidentally emptied a box of discs on her thumb and I forgot to remove my finger as I was shutting a door,   Very Ouch at the time but nothing but a bit of blackened nail now!!! 
The images was provided by my son's partner.
Today's image is in extras.