Duplex purchase in jeopardy due to fire in primary residence

[Susan Beard]

Hello, all of you experienced REI guys!
We’re trying to get in the game, but have hit a snag. Our plan was to sell our primary residence, after having made extensive upgrades, and use the equity to purchase a duplex. We plan to house hack. We went under contract on our home, and on a duplex we found to buy. Two mornings ago, and 10 days from the closing on our primary, lightning struck and burned out the entire garage on our home. Early estimates are @$100,000 damage. Now, the buyer of our home may back out, leaving the purchase of our duplex in question. Have any of you had any experience with something like this? What advice would you offer? 

Thanks for your feedback!