I wonder if someone disturbed the possums nest?
I was shocked to see a mother possum with her babies
in day time in my back yard.
Some neighbors were having bushes and trees cut down and
the possums nest was destroyed.
She was trying to protect her babies from Rocky.
She was wounded, and I was able to save a couple of
her babies and bring them to her. The mother never
even hissed at me. Her babies climbed up on her.
I was on the phone trying to find a vet
that would take them. (which none would)
By the time I got off the phone, she had climbed over over the fence.
I can only hope she and her remaining babies were ok.
(especially because everyone seems to have dogs in their yards)

Where I live we do not have a problem with possums carrying diseases
such as rabies.