One way that an author can build suspense in their work is through their use of foreshadowing, which is defined as planting hints about events that will occur later in the plot. This is certainly a strategy that Ercrich uses very well from the very first paragraph. Note how the narrator tells us at the beginning of the story raises our suspense by creating a mystery that is yet to be unfolded:

I would, in fact, tend to think that all memory of double somersaults and heart-stopping catches had left her arms and legs were it not for the fact that sometimes, as I sit sewing in the room of the rebuilt house in which I slept as a child, I hear the crackle, catch a whiff of smoke from the stove downstairs, and suddenly the room goes dark, the stitches burn beneath my fingers, and I am sewing with a needle of hot silver, a thread of fire.

Note how this quote leaves us with so many questions: why was her childhood house "rebuilt"? Why is the "thread of fire" so significant to her and why does it relate back to her mother's former life as a trapeze artist? It is foreshadowing like this that makes this story so suspenseful as the author plants tantalising hints of what actually happens later on to keep us reading.