The Walt Disney Company (DIS  ) has officially closed the doors of its popular theme parks and resorts Disney World and Disneyland "until further notice" due to the COVID-19 pandemic. This is the first time Disney has closed both locations since the September 11, 2001 terrorist attacks.

Disney will continue paying its employees through April 18. As of now, no reopening date has been announced.

"While there is still much uncertainty with respect to the impacts of COVID-19, the safety and well-being of our guests and employees remains The Walt Disney Company's top priority," said Disney. "As a result of this unprecedented pandemic and in line with direction provided by health experts and government officials, Disneyland Resort and Walt Disney World Resort will remain closed until further notice."

These temporary closings of Disney World in Florida and Disneyland in California should come as no surprise considering the current widespread implementation of social distancing practices intended to flatten the curve of the COVID-19 pandemic.

Social distancing and stay-at-home measures have been strongly recommended and even required and enforced in many areas across the country in an effort to slow the spread of the 2019 novel coronavirus SARS-CoV-2. The hope of world health experts and government authorities is that these preventative measures taken by businesses and the public will help hospitals not become overwhelmed with a surge in emergency cases and that, as a result, fewer deaths will occur overall.

Individuals who have paid for Disney World and Disneyland passes for the year will be eligible for a partial refund, or they will be able to have their passes extended, based on the amount of time the parks end up remaining closed.

In addition to Florida and California, Disney has also closed its park locations in Paris, France; Shanghai, China; Hong Kong; and Tokyo, Japan.

UBS analysts have estimated that if Disney had to shut down all of its parks worldwide for one month, the company could lose roughly $2 billion in revenue for the year. In the U.S. alone, Disney could miss out on $1.5 billion in revenue.