In which casualty case is it UNNECESSARY to notify the local Coast Guard Marine Safety Office?

A
Your vessel is backing from a dock and runs aground, but is pulled off by tugs in 30 minutes.
B
Your vessel strikes a pier and does $1,500 damage to the pier but no damage to the vessel.
C
A nylon mooring line parts while the vessel is tied up and kills a harbor worker who was on the pier.
D
A seaman is injured and in the hospital for four days.
E