? Hundreds of loans on office buildings are about to come due at a very bad time

? Loans were taken out in time of low interest rates and are now hard to refinance

? Too many of the loans defaulting could trigger banking crisis and hurt economy 

Billions of dollars in loans on office buildings that are about to come due could play havoc with the US economy after interest rates soared.

About $117 billion worth is expected to be due this year and needs to be repaid or refinanced, according to the Mortgage Bankers Association.