Mendy Morris, the electrician, had rewired a house. “OK, I’m finished,” he said to the homeowner. “I checked all the wiring and everything is installed properly.

Mr. Morris began taking his equipment, tools and reels of wire out of the house. He left some reels of wire in the street next to his van while he went inside to get the remaining tools.

Meanwhile, a big dog ran by and got entangled in one of the reels. The dog ran down the street with the wire caught in its coat and the reel bouncing around behind it.

Half a block away was a restaurant with outdoor seating. Many people were eating outside. As the dog ran by, the reel bounced up and knocked a plate and glasses off one of the tables.

“What was that?” exclaimed the surprised patron, Mr. Jacobs. “There goes my lunch!”

“Don’t worry, I’ll bring you a new one,” said the waiter politely. He went to the kitchen to order a new serving and returned with a broom and mop to clean up the mess.

“It was nice of the waiter to bring a new serving, but this is a very interesting question,” Mr. Jacobs said to his colleague. “Who is liable for the damage?”

“I don’t know that anybody can be held accountable,” said his colleague. “Nobody actually did the damage. The dog simply got stuck in the wire.”

“I’m not convinced,” said Mr. Jacobs. “People need to be careful with their animals and their property!”

The following week, Mr. Jacobs met Rabbi Dayan. “I encountered an interesting monetary question last week,” Mr. Jacobs said. He related the story and asked: “Who is liable for the damage?”

“The electrician who left the wire outside is liable,” answered Rabbi Dayan. “If the dog is owned and the table was on the private property of the restaurant, the dog’s owner also shares in half the liability.”

“Could you please elaborate?” asked Mr. Jacobs.

“The Gemara (B.K. 3b, 6a) teaches that if a person left his belongings outside and they were flung about by the wind, he is liable for damage they caused,” explained Rabbi Dayan. “This is an extension of esh (fire), which typifies damage that moves. The same is true of items that were dragged around inadvertently by animals. Thus, the electrician who left wire in the street that was dragged by the dog is liable for the damage that it caused” (Rema, C.M. 390:10; Sma 390:21, 25).

“And why is the dog’s owner also responsible?” asked Mr. Jacobs.

“Damage caused by an animal in the course of walking is called regel (foot),” replied Rabbi Dayan. “Items attached to the animal are included in regel. Thus, the dog’s owner is also liable for the damage done by the reel attached to his dog. However, regel is exempt in public property, so that the dog’s owner is liable only if the table was in the restaurant’s private property” (C.M. 390:1-3, 411:4; Shach 411:1; see Pischei Choshen, Nezikin 6:21[46]).

“But if the dog is partly responsible, why is the electrician fully liable when the dog is stray or if the damage was in a public domain?” asked Mr. Jacobs.

“This is a principle of Rabi Nassan (B.K. 53a),” replied Rabbi Dayan. “When two parties are responsible for damage and one party cannot be held liable, the other party bears the full liability. Therefore, if the dog has an owner, he shares the liability with the electrician. However, if the dog is a stray or the damage was in a public domain, the electrician bears full liability” (Gra 390:21; Pischei Teshuvah 390:1).