Yair was always looking for spare jobs to earn some extra money. One evening, he received a call from Mrs. Glazer.

“Our fridge and oven have gotten really filthy over the summer and need a serious cleaning,” she said. “I heard that you sometimes do this kind of cleaning.”

“Sure - usually Pesach time,” he laughed, “but I’ll do it for you.” He arranged to come the following afternoon.

Yair showed up the next day with his cleaning supplies. He removed the parts that could be easily taken off for more effective cleaning, including the doors of the oven. When everything was clean, he began to reassemble the pieces he had removed.

As he picked up one of the oven doors, the metal guard holding the glass fell off. The glistening glass fell to the floor and shattered!

Yair stood there, stunned. “How did that happen?” he asked himself.

He realized that he had picked up the door upside down. “That shouldn’t make a difference,” he thought. “I’ve done this many times!” He picked up the other door and carefully turned it upside down. The glass remained securely in its place.

When Yair gathered the shattered glass and the metal piece, he saw that the screws which had held the metal piece in place had corroded. He called over Mr. Glazer and showed him what happened.

“I picked up the oven door to return it to its place, but the screws fell out,” he apologized. “The glass slipped out and broke.”

“How could it have fallen out?” asked Mr. Glazer. “I see that the bottom guard is in place.”

“The top guard was loose, and I accidentally picked up the door up upside down,” explained Yair. “That shouldn’t make a difference, though. I’ll show you.” He picked up the other door upside down, and the glass remained securely in place.

“Still, had you picked up the door the right way, it wouldn’t have happened,” said Mr. Glazer. “So you are partly to blame.”

“Well, you didn’t warn me that the oven had loose, rusty parts,” countered Yair.

“We need to consult with someone on this,” said Mr. Glazer. “We can ask Rabbi Dayan.”

The two went to Rabbi Dayan and asked: “Is Yair liable for the glass that broke?”

“In principle, a worker who is entrusted to work on an item is considered a shomer sachar on it,” replied Rabbi Dayan. “He is not liable for circumstances beyond his control (oness), but is liable for preventable loss (geneivah va’aveidah).”

“What is our case considered?” asked Yair.

“Yair is not completely free of blame, since he held the door upside down,” said Rabbi Dayan. “On the other hand, picking up the door upside down is not supposed to pose any problem. Furthermore, he was entrusted with a defective door that had corroded screws without being warned.

“In a similar case, Chazal instituted that a porter who stumbles and damages his load is exempt unless he was negligent, such as if he tried to carry a heavy load that requires two people,” continued Rabbi Dayan. “If the porter tried carrying a load that was somewhat heavy for one person but doesn’t usually require two people, he is liable for half the amount. It can’t be called negligence, since often a single person does carry it, but it cannot be called uncontrollable, since the load was somewhat heavy for an individual (C.M. 304:1-4).”

“This isn’t a case of porters, though,” commented Mr. Glazer.

“Although this institution was said about porters, perhaps a similar idea could be applied to our case, since it’s difficult to ascertain clear responsibility,” said Rabbi Dayan. “Considering also that the glass door was defective and old, it would seem best to compromise that Yair cover a quarter to a third of the cost of the new glass.”

“What about Yair’s salary?” asked Mr. Glazer.

“There is a dispute in the case of the porters,” replied Rabbi Dayan (Sma and Taz 304:1). “Here, in any case, most of the salary is for the cleaning of the fridge and the rest of the oven.”