Fire-alarm belles.

• Position: San Diego Fire Engine Company 22, all women firefighters

When San Diego's Fire Engine Company 22 answers a call, their big red truck is missing a typical feature: a man. Engine 22, Division A (consisting of a captain, an engineer, a firefighter paramedic, and a firefighter) is among the few all-female fire crews in the nation. The four women were assigned to Engine 22 entirely by chance last October. Together, they work, train, sleep, watch TV, and cook meals at the station house, in 24-hour shifts, 10 days a month. They must also be able to...