A worker in a protective suit disinfects the interior of a train carriage in Mexico City
HOW COMMON ARE CITY LOCKDOWNS?
While the Wuhan lockdown is unprecedented in scale, other cities have experienced shutdowns and partial closures.
In 2009, authorities in Mexico City closed bars, cinemas, churches, offices and other public places to try to stop the H1N1 pandemic, also known as swine flu, from spreading.
But shutdowns mainly occur in response to extreme weather events, like floods and storms, which are set to become more common with the intensifying effects of climate change, say emergency response experts.
In such cases, transport suspensions are also common, albeit for different reasons.
In 2012, New York City shut down train and subway services and implemented bridge and tunnel closures as it hunkered down for Hurricane Sandy.
During environmental hazards, authorities generally focus on getting people out of harm's way first, said Mark Kammerbauer, an urban and architectural researcher at the Nuremberg Institute of Technology who studies disaster recovery.
But, he noted, residents could be told to stay put when there is not enough time to evacuate, like in the case of a flash flood.
"Essentially that means you are confined within the city," he said. Pictured: A worker in a protective suit disinfects the interior of a train carriage to prevent the spread of the Influenza A (H1N1) virus, formerly referred to as swine flu, at the Constitucion de 1917 subway station in Mexico City May 7, 2009. REUTERS/Daniel Aguilar