Despite the focus on drug shortages, the nationwide decline in available saline bags was one of the most daunting shortages in recent years. It started in the aftermath of Hurricane Maria, which devastated many islands in the Caribbean in September 2017, including Puerto Rico, where nearly all of the U.S. supply of saline bags was manufactured. That disaster revealed health care’s fragile supply side in the United States, and how manufacturing consolidation can lead to major shortages for basic medical supplies. Understanding how health care manufacturing works—and how it doesn’t—could unlock the answers to preventing these shortages in the future.