Bava Kama page 6a. Rav Shach asks why the Rambam does not bring the law of his stone knife or burden that he left on top of a roof and they fell in a common wind and they did damage after they were already abandoned that he is liable. The answer is that the gemara originally thought one must to to do and act in order that he be liable for causing damage. But after we learn about the wall and tree that fell and did damage that he is liable without his doing any deed, all the more so in our case of the stone on the roof when he did a deed by putting them on the roof. A similar answer Rav Shach provided about why the Rambam did not mention the law of a pit that is being kicked around by the feet on people in a public domain. The reason this is not brought is the same. The question I have on this is the question who is liable in the case of a rolling pit? Even if you say the one who put it there is liable, but still there is the second person. Tosphot in fact says it is the one kicking the pit thar is liable.So you cannot learn that he is liable by negligence since he is not negligent. A second problem is that even in way that we learn before we learn about the wall and tree that feel that the obligation for the stone on the roof is from pit and fire.so that might be a gap too wide to cross to learn that the stone of the roof from the wall and tree. however, I think Rav Shach does answer this last question himself. It is the first question that I think might be a good question unless we assume it simple that only the one who put the rolling pit in the public domain is liable.Although it is clear that the second person who is pushing the pit is doing it in an even more serious way than a negligence, and that he is clearly doing it intentionally, I still have a problem because it is the first person who committed the crime and the second person who caused the problem who should share the responsibility and each pay half. Not just the first person------------------------------------בבא קמא דך ו ע''א page 6a רב שך asks why the רמב''ם does not bring the law of his stone knife or burden that he left on top of a roof and they fell in a common wind and they did damage after they were already abandoned that he is חייב. The answer is that the גמרא originally thought one to to do and act in order that he be חייב for causing damage. But after we learn about the כותלand אילן that fell and did damage that he is חייב without his doing any deed, all the more so in our case of the stone on the roof when he did a deed by putting them on the roof. A similar answer רב שך provided about why the רמב''ם did not mention the law of a pit that is being kicked around by the feet on people in a רשות הרבים. The reason this is not brought is the same. The question I have on this is the question who is חייב in the case of a rolling pit. Even if you say the one who put it there is חייב but still there is the second person תוספות in fact says it is the one kicking the pit thar is חייב. So you cannot learn that he is חייב by negligence since he is not negligence. a second problem is that even in way that we learn before we learn about the wall and tree that feel that the obligation for the stone on the roof is from pit and fire.so that might be a gap too wide to cross to learn that the stone of the roof from the כותל ואילן. However, I think רב שך does answer this last question himself. It is the first question that I think might be a good question unless we assume it simple that only the one who put the הור המתגלגל in the רשות הרבים is חייב. הגם שזה ברור שאדם השני שמגלגל את התקלה עושה זה באופן אפילו יותר חמור מפשיעה אלא ברור שהוא עושה את זה במזיד, עדיין יש לי קושיא בגלל ש הוא אדם בראשון שפשע ואדם השני שדוחף התקלה צריכים לחלק את האחריות ושכל אחד ישלם חצי, לא רק הראשון