Unless the contract was contingent upon their personal disposition, the sellers may have a problem. If you are near the closing date, you have most likely expended a fair amount of money for appraisal, survey, inspections, etc. At a minimum, the seller should be very happy to reimburse you for all out of pocket expenses in exchange for a mutual release. If not, contact a local real estate attorney for more options.
For more on this topic, please email us at smith@realtor.com