Bava Kamma, Chapter 5, Mishnah 5. From here onward, the Mishnah begins to deal with the primary category of damage called a pit - a hole in the ground. Its basis is in the verse: "If a man shall open a pit, or if a man shall dig a pit and not cover it, and an ox or a donkey falls in there - the owner of the pit shall pay." This means: A person who uncovered an existing pit or dug a new pit and did not cover it, and an animal fell into it - the owner of the pit pays for the damage.
Which pit the Torah is discussing:
The Gemara brings a baraisa that discusses this question. According to Rabbi Shmuel, the Torah is dealing only with a pit that was dug in the public domain. However, Rabbi Akiva - who is the Tanna of our Mishnah - holds that the liability also includes a pit dug in the private domain, on a person's private property. Our Mishnah follows the approach of Rabbi Akiva, and therefore will explain how a person becomes liable for a pit that he dug on his own property. The foundation of this is: Even though he dug with permission and full right, since the place was his at that time, if he subsequently declared the area around the pit ownerless and turned it into part of the public domain - it turns out that he introduced a hazard into the public domain, and is liable for it.
Two inferences from the verse lie at the foundation of this matter:
The verse lists two separate actions: "Vichi yiftach" - one who opens a pit that another dug, and "o ki yichreh" - one who digs the pit himself. Seemingly, if he is liable for uncovering the pit of another, it is a kal vachomer that he would be liable for a pit that he dug from the outset. From this, the Gemara derives that the matter does not depend on who dug the pit, but on who creates the hazard in the public domain. Everything therefore depends on the public domain, and the private domain has no relevance to this at all. This is the Torah source for a pit in the public domain.
On the other hand, it states later on: "Baal habor yeshalem" (the owner of the pit shall pay). Since a person is not called an owner except regarding something that belongs to him, Rabbi Akiva proves from here that even one who digs in his own private domain and subsequently declares the area around the pit ownerless is liable, and it turns out that the Torah is referring to both cases. Rabbi Shmuel disagrees and holds that the entire passage deals with a pit in the public domain, and "the owner of the pit" means that the Torah assigns him ownership. In any event, our Mishnah follows Rabbi Akiva, that both the public domain and the private domain are included.
Two introductions to the wording of the Mishnah:
The location of the pit is determined by its opening: If the pit was dug diagonally, such that the cavity itself - the cavity into which one falls, or where the water is gathered - is located in one domain, while the opening is located in another domain, the pit is considered to be situated in the domain where the opening is located.
Two danger factors in a pit: The first is the chavatah (impact) - the blow that the one falling suffers from the bottom of the pit. The second, and the more fundamental one in terms of its lethality, is the hevel (fumes) - air or gas that has no available oxygen, which accumulates at the bottom of the pit. One who falls into it cannot breathe and suffocates.
Even in our times, tragic stories are known about people who fell into pits connected to sewage or animal waste and suffocated inside them. Although it seems that the Torah is not dealing here with a pit designated for waste, and such gases would not be found in it, it is possible that other gases rise from the ground and accumulate there, and it is possible that once the pit is dug, people even cast excrement into it. In any event, in a deep pit, gases that are heavier than air accumulate. This can be seen from dry ice that is evaporating: The carbon dioxide spills over the table and goes downward, because it is heavier than the air around it. Such a gas, which cannot be breathed, will remain inside the pit and render it dangerous.
Thus, there are two separate matters: The hevel - the inability to breathe at the bottom of the pit, and the chavatah - the force of the blow. In a deep pit with a gentle slope, for example, there will not necessarily be a problem of chavatah, since there is nowhere to fall, and nevertheless, hevel may accumulate at its bottom.
The four types of pit for which one is liable:
"Hachofer bor birshus hayachid u'fischo lirshus harabim" - one who digs a pit in the private domain and its opening is to the public domain, referring to a pit that was dug in a person's private courtyard, but the opening through which one falls into it is located in the public domain. Since the opening is there, the pit is considered a pit of the public domain.
"O birshus harabim u'fischo lirshus hayachid" - or in the public domain and its opening is to the private domain, where the main excavation, the subterranean part, is located in the public domain, while the opening through which one enters it is found in the private domain, in his private courtyard. Rashi explains, and the Bartenura also learns this way, that it refers to a case after he declared the area around the pit ownerless. Because as long as the opening is entirely in his domain, there is no danger here: If a person had fallen into the pit in his courtyard, the owner of the pit could have claimed, "Who permitted you to enter and trespass in my courtyard?", and he would be exempt. But once he declared the surroundings of the pit ownerless, he no longer has this claim, and he has created a dangerous hazard - and is liable even for this.
"Birshus hayachid u'fischo lirshus hayachid acher" - in the private domain and its opening is to another private domain. According to Rashi and the Bartenura, it refers to a person who has two courtyards, a front courtyard and a back courtyard, and dug a pit extending from one to the other. Even though both of them are his and everything is his private property, if he subsequently declared the area around the opening of the pit ownerless - he is liable for one who falls into it. Tosafos is not comfortable with the wording "another", and explains that the intention is to the courtyard of another person, but the foundation is the same.
It is worth noting in passing: One who digs a pit in his private property within four tefachim - about thirty to forty centimeters - close to the public domain, the pit is considered dangerous even without his having declared its surroundings ownerless, because those walking in the public domain are liable to fall into it by mistake, and he bears responsibility.
"Hachofer bor birshus harabim" - one who digs a pit in the public domain. The simplest case: a person digs a hole or a pit in the public domain. This refers to someone who dug without permission, because if the municipality had instructed him to dig a well, and after digging he handed the well cover over to them, it is obvious that he is not responsible for anyone who falls into it. But one who digs a pit in a public area on his own initiative is completely responsible. This case was left for last because it is the greatest novelty: in a public area, there is room to ask why he should be liable, since the space is not his, and this does not align with the rest of the tractate thus far, which dealt with 'property that causes damage' - a person's property that caused harm. Here, the public domain is not his property, and nevertheless, the pit is attributed to him and he is liable.
In all four of these cases: "Venafal lesocho shor o chamor vames - chayav" - and an ox or a donkey falls into it and dies, he is liable. The Mishnah will teach later that there is no difference between one animal and another, and all animals are included; it specified an ox and a donkey here because these are the examples that appear in the verses themselves. The one liable is the person responsible for digging the pit, and later in the chapter we will learn additional details regarding the law of one who uncovers a pit or leaves it uncovered. The general rule is that the creator of the public hazard is the one who pays the owner of the animal that died.
There is no difference in the form of the excavation:
The Mishnah continues: "Echad hachofer bor, siach, me'arah, charitzin u'ne'utin" - whether one digs a pit, a ditch, a cave, trenches, or wedge-shaped ditches. The verse specified a pit, but there is no practical difference regarding the form of the excavation:
Bor - a round, deep hole in the ground, which was used for storing water.
Siach - a long, narrow ditch.
Me'arah - a square space in the ground that has a cover on top, like a roof.
Charitzin - square holes that do not have a cover on top.
Ne'utin - cone-shaped excavations, narrow at the bottom and wide at the top.
In all of these, he is liable. Even though the word "bor" specifically describes a round, deep hole, this is not the point: for any space that is deep enough for fumes to accumulate, those gases that cannot be breathed - he is liable, and even for ne'utin, which can be shallow. And even if a person were to fill the excavation with sponges, so that one who falls into it would not be hurt at all, it makes no difference, because one could still suffocate from the gas found at its bottom.
"Im kein lamah ne'emar bor" - if so, why does the verse state "a pit":
If there is no difference in the form of the excavation, why did the Torah specifically single out "a pit"? It could have used the term "excavation" - any dug-out space. During the time of the Sages, they dug various types of pits, and each of them had its own name, and therefore the question is asked why the round, deep pit was specifically chosen.
The Mishnah's answer: "Mah bor sheyesh bo kedei lehamis - asarah tefachim, af kol sheyesh bo kedei lehamis - asarah tefachim" - just as a pit, which has enough depth to cause death, is ten tefachim deep, so too anything that has enough depth to cause death is ten tefachim deep. In a regular pit, everyone knows that a person does not dig a water pit that is not deep enough to store a significant amount of water, meaning at least ten tefachim - about a meter. At such a depth, it has "enough to cause death": an animal that falls in is liable to suffocate and die, or break its neck and die. And just as with a pit, so too with any excavation in the ground: as long as its depth is ten tefachim, there is a possibility that fumes will accumulate in it that could kill animals.
"Hayu pechusin me'asarah tefachim" - if they were less than ten tefachim:
The Mishnah continues: "Hayu pechusin me'asarah tefachim, venafal lesocho shor o chamor vames - patur" - if they were less than ten tefachim, and an ox or a donkey falls into it and dies, he is exempt. If the depth of the pit is less than ten tefachim, and another person's animal fell into it and died, the digger is exempt, because it is not a common occurrence for an animal to suffocate and die or suffer a fatal break from a fall of less than ten tefachim. We therefore attribute the death to another, external factor - perhaps it had a weak heart and the like - and the digger is considered a victim of circumstances beyond his control, and it is not his responsibility.
"Ve'im huzak bo - chayav" - and if it was injured in it, he is liable. If death did not occur but only injury, such as if the cow's leg was broken, and similarly if a person or another animal was injured, the one responsible for digging the pit or uncovering it is liable to pay the owner of the animal that was injured in its fall, subject to the limitations and details that will be explained in the upcoming Mishnayos.
In summary: In this Mishnah, we learned the fundamentals of the primary category of damage, Pit: its source in the verses, "If a man opens a pit, or if a man digs a pit", and the dispute among the Tannaim whether the liability is only in a public domain or even for a pit dug in a private domain where the surrounding area was declared ownerless - which is the view of Rabbi Akiva, and the view adopted by our Mishnah. We discussed two introductory points: the location of the pit is determined by its opening, and its two factors of danger - the impact and the fumes. We enumerated the four types of pits for which one is liable, and we learned that there is no difference in the shape of the excavation - a pit, a trench, a cave, ditches, or wedges - but only in the depth: ten handbreadths, which is enough to cause death. For less than ten handbreadths, one is exempt for death, but liable for injury.
In the following Mishnayos, we will continue with the details of the laws of a pit: the limitations of liability for injury, and the law regarding one who uncovers a pit and leaves it uncovered.