Our CBA doesn’t say anything about an act of god. It says “circumstance over which the company does not have control”.

From Spirit’s 2019 annual report:

“Airlines are often affected by factors beyond their control, including: air traffic congestion at airports; air traffic control inefficiencies; major construction or improvements at airports; adverse weather conditions, such as hurricanes or blizzards; increased security measures; new travel related taxes or the outbreak of disease, any of which could harm our business, operating results and financial condition.

...

Similarly, outbreaks of pandemic or contagious diseases, such as Ebola, measles, avian flu, severe acute respiratory syndrome (SARS), H1N1 (swine) flu, Zika virus and Coronavirus, could result in significant decreases in passenger traffic and the imposition of government restrictions in service and could have a material adverse impact on the airline industry.
”

I would bet the company’s position is that they are not obligated to provide furlough pay.