U.S. Bureau of Labor Statistics

Margaret J. Krauss / 90.5 WESA

Steve Kelley spends his nights working more than twenty stories up. It can be scary sometimes—all alone, high off the ground in Pittsburgh’s Gateway Center—especially when he can see lightning flash through the huge windows. But most often it’s peaceful, says the union janitor with SEIU 32BJ: “Just the work and me.” Night work is essential to the economy, but it can often be invisible, even hazardous.