Answer:
It was the white glove he saw that made him cry.
Explanation:
Mr. Frank breaks down crying because there's a lot of memory in that place and finding that white glove just made them all come back to him. According to the text it states, "As he starts back for his rucksack, his eye is caught by something lying on the floor. It is a woman's white glove. He holds it in his hand and suddenly all of his self-control is gone. He breaks down, crying."
