Bava Kamma 50 ~ Ten Tefachim to Death

משנה, בבא קמא נ, ב

החופר בור ברה"ר ונפל לתוכו שור או חמור חייב אחד החופר בור שיח ומערה חריצין ונעיצין חייב א"כ למה נאמר בור מה בור שיש בו כדי להמית עשרה טפחים אף כל שיש בו כדי להמית עשרה טפחים היו פחותין מעשרה טפחים ונפל לתוכו שור או חמור ומת פטור ואם הוזק בו חייב

If a man digs a pit on public ground and a bull or a donkey falls into it, he is liable for damages. Whether he dug a pit, or a ditch, or a cave, trenches, or wedge-like ditches, he is liable for damages that his digging caused. If so why is pit mentioned in the Torah? It is to teach the following: just as a standard pit can cause death because it is ten tefachim [handbreadths] deep, so too for any other excavation to have sufficient depth to cause death, it must be ten tefachim deep. Where, however, they were less than ten tefachim deep, and a bull or a donkey fell into them and died, the digger would be exempt.  But if then animal was only injured by falling into them, the digger would be liable. (Mishnah, Bava Kamma 50b.)

The Highest Fall Survived (without a parachute)

According to The Guinness Book of Records, Vesna Vulovic  holds the world record for the highest fall survived without parachute. And how high was that? Really, really high:

Vesna Vulovic (Yugoslavia) was 23 working as a Jugoslavenski Aerotransport hostess when she survived a fall from 10,160 m (33,333 ft) over Srbsk, Kamenice, Czechoslovakia (now Czech Republic), on 26 January 1972 after the DC-9 she was working aboard, blew up. She fell inside a section of tail unit. She was in hospital for 16 months after emerging from a 27 day coma and having many bones broken...She never suffered any psychological trauma as a result of the incident, and never experienced any fear of flying. She is still alive today, and flies with some regularity. However, Vulovic does not consider herself lucky. Thirty years after the crash, in an interview she said:  ''I'm not lucky. Everybody thinks I am lucky, but they are mistaken. If I were lucky I would never have had this accident and my mother and father would be alive. The accident ruined their lives too."

In my years as an emergency physician I saw countless patients with injuries from falls. Most injuries were relatively minor, but several of my patients died. Is there a minimum height below which a fall would result in a trivial, or at least a non-fatal injury? Based on my experience, the answer is an unequivocal no.  A fall from any height, however low, can result in a serious or fatal injury, and that includes a fall from standing. But that's just my experience. What does the medical literature say? Does it agree with the assertion of the Mishnah that a fall below 10 tefachim (about 76 cm or 30 inches) cannot result in a fatal injury? Let's take a look...

At autopsy, classic findings in falls from height include aortic lacerations and vertebral compression fractures, as well as ring fractures of the skull base...Severe head injuries most frequently occurred in falls from heights below 10m and above 25m, whereas in the group that fell from 10 to 25m, few head injuries were seen and they rarely were the cause of death.
— Turk, EM. Tsokos, M. American Journal of Forensic Medical Pathology 2004;25: 194–199

The Epidemiology of Falls

Falls are very common. In the US they make up about a third of the injuries that lead to an ED visit in the each year - that's close to eight million visits.  In keeping with my experience, national data shows that only about 1% of all fall injuries that come to the ED are profound.  And here's another interesting finding that is in keeping with my own clinical experience: it's close to impossible to predict what kind of injury a person will have based on the height of the from which the victim falls. In a paper that examined over six-hundred fatal falls that occurred in Singapore, the authors noted that  

...there was much variability in the injury severity scores, in relation to the height of fall... Thus, a subject who had fallen through a height of 10 m, with primary feet impact, could have sustained complete traumatic transection of the thoracic aorta, with haemorrhage into the pleural cavities but little else by way of serious injury; while another, similar, subject could have fallen through 20 m and had sustained multiple head, thoracic and abdominal injuries...

In fact theses authors had a very hard time coming up with a model that describes the height of fall and indicators of injury severity other than to give this rather useless nugget: "Our findings suggested that the height of fall was significantly associated with ... the extent of injury." Well thanks. But it's one thing to fall 10m or more (that's over 30 feet for those if you not on the metric system). What about falls from less lofty heights?

Falls Down the Stairs, and Falls from Standing

Let's start with falls down the stairs. German forensic pathologists published a paper in Forensic Science International that addressed this aspect of falls in 116 fatal cases.  The most frequent victim was a man between 50 and 60 years old, and brain and skull injuries were the most common cause of death. About 8% broke their spines as they fell and (shocker) many were intoxicated. So stairs can kill.  

What about falls from standing? Well back to the German forensic pathologists, who this time published a retrospective analysis of 291 fatal falls. Of these, 122 -that's 42% - were falls from standing. About 80% of these ground-level falls were not immediately fatal, and the victim survived anywhere from three hours to almost a year post injury. Almost 60% of the men and 11% of the women who sustained a fatal ground-level fall were (shocker again) intoxicated.  So there we have it. The medical literature demonstrates that falls from standing can certainly be lethal.  Especially after kiddush.

From Thierauf A. et al. Retrospective analysis of fatal falls. Forensic Science International 2010. 198. 92–96. Forgive the English. It wasn't their first language.

From Thierauf A. et al. Retrospective analysis of fatal falls. Forensic Science International 2010. 198. 92–96. Forgive the English. It wasn't their first language.

The US federal government has also weighed in on the matter. OSHA, the Occupational, Safety and Health Administration has a ruled that a duty to erect fall barriers to protect employees only applies when the fall will be more than 6 feet (1.8m).  

Each employee who is constructing a leading edge 6 feet (1.8 m) or more above lower levels shall be protected from falling by guardrail systems, safety net systems, or personal fall arrest systems.
— 29 CFR 1926.501

Back to the Mishnah

The Mishnah rules that only a pit more than 30 inches (ten tefachim) deep is lethal should someone  - or some animal - fall in. We have seen that this has no medical validity. But that doesn't really matter for a legal system.

Consider the legal limit for alcohol allowed when driving. In my home state of Maryland, it is 0.08%, (though of course your ability to drive safely is impaired at levels considerably lower). So what happens if a driver is stopped and his blood alcohol content is 0.07%? Well, it's simple: he is not legally impaired and so may continue to drive.  Is this an indictment of the Maryland drunk driving laws? Not really. Maryland, like all other states, sets its blood alcohol limit; if a driver is close, but below the limit, no penalty follows.

Jewish law too, has to set limits and measures, below which legal penalties do not apply.  The Mishnah's ruling that a pit is only fatal if it is more than 30 inches deep is a legal one - not a medial one.  It works to set limits and insure public safety. A person who digs a pit only 9.5 tefachim deep is not legally liable, and a pit that is a full 10 tefachim deep is certainly rarely lethal if a person accidentally falls in.  But for the sake of public safety a ruling  - arbitrary though it is - had to be made.  So be careful when you dig your pit in a public thoroughfare.