You are employed at a tennis club as the head teaching pro. According to your job descriptions, you are responsible for making sure that the assistant pros run instructional drills properly. Since you are very busy with your own lessons, you have not watched any of the drill sessions run by one of the assistant pros. If you had observed any of the drill sessions, you would have seen that the assistant pro was not following good safety practices as he set up the overhead drills. He was having students hit overheads while the people on the other side of the net were doing another drill. Someone was hit by an overhead and was seriously injured.

Question:

What liability can exist?