What is the city of tragedy in the book The Proud Taste for Scarlet and Miniver?

The word tragedy is only used once in this book, on page 56, to refer to the incident with Eleanor and the Amazons on the plateau. This event happens on a plateau in the wilderness and not in a city at all.
So let's examine some of the other cities in the novel to see which one could be considered a city of tragedy.
First is Paris, referred to by Abbot Suger as the "city of light" (p. 25), which is a common phrase used to refer to Paris. He also calls Paris a "city of ideas" and the "city of the University" (both p. 25). Nothing especially tragic happens in Paris in this book.
Next in the book is Vitry. This could be considered a city of tragedy as a tragedy occurs there: King Louis set fire to the city's roofs and, instead of fleeing, the people took shelter in their church. When the church collapsed, these 1300 people died because of Louis's actions. He repented and began living a simpler life, wearing monks' robes and deciding to go on a crusade to Jerusalem (considered a holy action but in reality, just another violent invasion). This is a major event in the book, and this incident is a big catalyst for the collapse of Eleanor and Louis's marriage.
The next city described in the book is Constantinople. It is described as "magnificent," "gay," "glittered," and "dipped in a rainbow," a "city of color, but also of ceremonies" (all p. 44).
The next city in the book is Damascus. It is there that Louis's crusade ends: "The plan to take Damascus was a failure" (p. 59). This could be considered a tragedy; doubtless many people died. But none of this is described in detail in the book; this is the last time the city is described.
The final city mentioned in the book is Jerusalem. This city is never shown in the narrative, only mentioned. It is considered by the characters telling the story to be a "holy city" (p. 148). Despite this, capturing or holding the city is the objective of them multiple crusades which happen throughout the book. So it could also be considered a city which gave rise to tragedy despite none of the story actually being set there.
If this is a question raised by an assignment, it may be that your teacher has used the specific phrase "city of tragedy," in which case you should review your course materials or ask your teacher about it.