From a review of Americans in Paris:
Edith Wharton settled in Paris in the 1890s and was there to see the city transformed by the mobilization that began France's engagement in World War I. From the comfort of a window table in a restaurant on the Rue Royale, she sees the street flooded with conscripts on foot, headed for the railway stations, and "every cab and taxi and motor-omnibus had disappeared. The War Office had thrown out its drag-net and caught them all in."
She describes watching "the gradual paralysis of the city." Within the first week, she writes, two-thirds of the shops had closed, with a notice indicating the patron and staff were at the front, and most of the hotels had closed or "were being hastily transformed into hospitals," anticipating the wounded. "In a night, it seemed, the whole city was hung with Red Crosses."