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WUHAN, China — When the coronavirus emerged in Wuhan, residents in a rising suburb on the city’s rural edge thought they were safe. Zuoling New Town, a bustling community of retired farmers, factory workers and young, white-collar professionals, was 22 miles from the market where the outbreak appeared to have arisen. The apartments had sprung from former farm fields, far beyond the alleys of old Wuhan.

But as the virus spread, Zuoling emerged as a stubborn hot spot of infections in Wuhan, and a somber lesson in how the state’s vast effort to contain the virus left some communities acutely vulnerable. The leadership’s top-down campaign relied on grass-roots mobilization, and the very newness and isolation of Zuoling proved to be a weakness, depriving residents of food supplies, medical care and labor during crucial weeks.

Residents crammed into the only large supermarket to stock up. Those worried about fevers crowded the local, government-run clinic, and many were sent back to their high-rise homes, sometimes spreading the virus. The nearest major public hospital assigned to take patients was 10 miles away, making it more difficult to get treatment, especially without a car.

“I never imagined that this would hit our home,” said Zhang Jin, a 47-year-old school bus driver in Zuoling. His mother, Yan Yinzhen, who was living with him, contracted what doctors believed was the coronavirus, possibly from a neighbor. Mr. Zhang, his wife and father all later fell ill.