By the Grace of G-d 13th of Shevat, 5743 Brooklyn, N.Y.

Blessing and Greeting: 

I received your letter [of the 4th of Shevat] and may G-d grant that henceforth your letters, as all letters exchanged by Jews, should contain only good tidings, the kind of good that is revealed and obvious. 

Needless to say, you are right that a Jew should learn from everything a lesson how better to serve Hashem, in accordance with the well known teaching of the Baal Shem Tov,¹ and in keeping with the teaching of our Torah, as to what this service אני נבראתי לשמש את קוני² consists of. At the same time, the Torah demands that it should be עבדו את ה’ בשמחה.³

Specifically, you surely know about the mitzvah of ma'ake. This includes not only having guarding rails or a fence around one's roof, but also similar precaution in similar situations, such as having a fence around a pool, to prevent the kind of tragedy which you write about. This is quite obvious. 

It is not easy to offer consolation in such a case, but I trust that you may have heard from your husband or others, the story that also appears in Seforim, that one of our great luminaries who was great also in chochmo nisterah, about a child of frum Jewish parents who died young. He was asked to give an explanation why this innocent child had died so young. He answered that the child's soul had already been on earth in a previous life, but for some reasons remained short of several years. Hence it was necessary to come down to earth again to make up for those years, and the parents had a special zechus to bring up that child during the allotted time in accordance with the Torah, to eat kosher food, recite brochos, etc. 

Insofar as you are concerned, being a teacher, by dedicating yourself fully, as you write, to teaching Jewish children and doing it with vitality and joy, you will be building "fences" around Jewish children, to protect them from the dangers of harmful outside influences, to which every Jewish child is necessarily exposed as a member of a small minority of people living among the peoples of the world. 

I want to emphasize again the importance of doing this sacred work, as all matters of Torah and Yiddishkeit, with joy and gladness of heart which, in addition to this being a must in itself, also assures infinitely more hatzlocho. 

As requested, I will remember you at the holy resting place of my father-in-law of saintly memory, whose Hilulo we have just observed. 

With blessing, 

M. Schneerson