Paying employee salaries is a worker's obligation according to the wage and labor agreement but the current conditions are different. Workers do not work, as usual, not paying a full salary is the best solution imo.
I agree, depending on the country, some basic money should be given to workers so that they could buy food and necessities. But it's not an obligation of casino owners only. The owners should pay a part but another part should be paid by the government. Where all those taxes go, after all? It's partly to not let people die of hunger in times like these.
I think that a casino (or any other enterprise) should not pay at all during quarantine/state of emergency. This is a force majeure circumstance and here payments must be made by the government - this is its responsibility and duty. And we must not forget that the casino cannot print money from the air (even in emergency cases) and the government can.