Unprecedented deep cleaning for NYC subway

The New York City subway system, known for its 24-hour, seven-day-a-week service, took the incredibly rare move to stop its trains overnight for a massive deep cleaning and disinfecting operation.

A small army armed with backpack disinfecting machines and other apparatus, its operators say the move is the biggest cleaning effort the system has ever seen.

Sally Librera is with the city's transit authority.

"We're trying out anti-microbial treatments to keep surfaces virus-free, longer. We are looking at ultraviolet light technology that can immediately eradicate viruses. We're looking at electrostatic sprayers and using foggers to improve the productivity and increase the speed with which we're working so that we can minimize the disruption to customers."

The operation kicks off a wider day-long cleaning effort.

The city says that it's also been talking to some foreign transportation systems to learn best practices, as something of this scale is quite new to New York.

Right now ridership on the trains has plunged about 90%, but even when the lockdown starts to lift most commuters may not be able to use it due to social distancing.

Savills -- the real estate giant -- predicts that keeping commuters six feet apart will mean only about 1 in 5 of them will be able to make it onto a train before it reaches capacity.