Today on the Jewish calendar we enter into a period known as the Three Weeks, a period of mourning and sadness that culminates in the observance of Tisha B’Av, the Ninth of the Month of Av, the date that marks of the destruction of the ancient Temples in Jerusalem.

Jewish tradition holds that both of the ancient Temples were destroyed on Tisha B’Av, the first in 586 BCE and the second in 70 CE. As Jewish lore holds these buildings as the most sacred and central–the place where humanity and the divine were the closest, the place that served as the central communal institution–noting their destruction is a day of communal sadness and mourning.

This day then becomes a day to reflect on a variety of other sufferings that have happened to the Jewish community over the years, and a day to reflect on the causes of societal collapse. Numerous commentaries about the destruction of the Temples point to interpersonal conflict, “baseless hatred,” and a breakdown of ethical norms and decency as providing the fodder for the events of Tisha B’Av, a reminder that sometimes communities fall apart not only because of external pressures but internal failings.

But our communal mourning really begins on the 17th of Tammuz, a minor fast day and observance on our calendar. [The 17th of Tammuz was actually yesterday, but since we do not observe fast days on Shabbat–except for Yom Kippur–the observance is pushed back a day.] Historically, the 17th of Tammuz is linked to the breaching of the walls of the city of Jerusalem as part of the Roman siege of Jerusalem in the first century CE.

But if Tisha B’Av is the focal point of our communal mourning, then why do we also observe the 17th of Tammuz?

The 17th of Tammuz is “the event that led to the event;” the fall of the walls of Jerusalem led to the fall of the Temple itself. So, in a way, our Jewish calendar is reminding us that while we need to remember the main event, we also need to remember the smaller events that preceded it. The fall of the walls of Jerusalem was the warning sign that a greater destruction was on the horizon, so observing the 17th of Tammuz is a reminder to pay attention to the warning signs we see in our society.

Currently, in another place and time, in our country today, we are seeing many warning signs of a deeper destruction at hand. Xenophobic and racist rhetoric is being put forth by the highest levels of our government. Policies are being implemented to those seeking refuge in our country that are hurtful to individuals and families. Regulations that would slow the change in our climate are being rolled back. All of these in their own right are harmful acts. And they also serve as warning signs for something worse to come.

Jewish tradition teaches that whether societies survive or fall is in our hands. As we note the breaching of the walls of ancient Jerusalem, we would be well served to pay attention to the warning signs we see in our own day and age, in order to avert a worse destruction.