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Mounting concern over the new coronavirus outbreak has caused school closures and movie premiere pushbacks, and now the crisis' effect on the aviation industry is drawing comparisons to 9/11.

Southwest Airlines CEO Gary Kelly told CNBC on Thursday that the company has lost several hundred million dollars in a week's time thanks to a decline in bookings amid increasing fears over COVID-19. Kelly added that the drop-off was "noticeable" and "precipitous" and has continued declining on a daily basis.

When prompted by CNBC's Phil LeBeau over whether the drop was reminiscent of former dips in demand spurred by the 2003 SARS outbreak or the events of Sept. 11, 2001, Kelly said the new coronavirus outbreak was more like the latter.

"It has a 9/11-like feel," Kelly said.

He explained that post-9/11 travel fallout was motivated by "fear" rather than being economically driven, saying fear is "really what's manifested this time" with the new coronavirus outbreak.

Kelly told LeBeau he thought the dip in bookings was an "overreaction" but that Southwest is financially prepared to handle the fallout.

The outbreak's effect has been felt heavily in the U.S. stock market, which has rotated between sinking and soaring over the last week, and it has caused at least 11 U.S. deaths and four states to declare emergencies.