The news follows Tesla's announcement about closing the Fremont factory and New York factory on March 24, but is quite surprising, as Tesla did not give any sign - on March 19th - that the Gigafactory will also be closed. At the moment there is also no official comment from Tesla.
Here is the statement from Panasonic via TechCrunch:
"Panasonic is committed to safeguarding the health and well-being of every employee. The Panasonic factory in Sparks, Nevada will begin ramping down operations early next week and will then close for 14 days. Employees impacted by the closure will receive full pay and benefits for the 14-day period. In the meantime, Panasonic has enacted several measures to enhance the cleanliness of the facility, encourage social distancing, and enable simple, safe and effective behaviors. During the 14-day period, the facility will undergo intensive cleaning."
In other words, all major Tesla plants will soon be temporarily closed, although the company will probably still perform some minor, highly important operations at those sites.
The Gigafactory reportedly employed 3,500 people and besides battery cells, was producing battery packs, electric motors and energy storage products.