The office property sector is in trouble as many workplaces remain empty, and that threatens to spark a number of economic problems, including more pain at the country's banks.

With so many people still working from home, companies are cutting back on office space. That spells trouble for small businesses that depend on foot traffic.

Shares in the midsized lender continued to tumble as fears grow about First Republic's financial health grow even after it received a $30 billion lifeline from its bigger rivals last week.