What is a short-summary of the story, The Swim Team, from the collection, No One Belongs Here More Than You?

In the story, The Swim Team, the narrator recalls a time in her life when she lived and worked in a small town. She befriended her elderly coworkers. When she learned that none of them knew how to swim, she endeavored to teach them. Because they did not have a pool or a nearby body of water, she taught them on the floor of her apartment. The narrator has not seen them in years, and she assumes they have all died of old age.