Problems with the ductwork

When you live on the east coast, you are all to aware of the hurricanes that threaten your home on an annual basis.  Everyone, for the most part, has an emergency bag packed and an evacuation plan in place.  They know that the storms can be devastating and loss of life is a real treat. The area where I live was greatly affected by Hurricane Matthew in 2016.  Some people are still feeling its effect and the battle with insurance companies for payment is maddening. My in-laws are among those people still dealing with the remnants. When the hurricane roared through our area my in-laws home that sits on a coastal marsh was impacted by way of flood waters. Unfortunately, this included the ductwork for their HVAC system that was located underneath the house. As the flood waters rose it completely flooded the HVAC ductwork. When they receded, they left behind a moldy, wet mess and damaged the HVAC unit itself.  They had the system checked and it seemed to function normally but they did not have the ductwork checked.  They just assumed that it would dry out like everything else and be fine. My in-laws did not see the extent of the damage until a couple of weeks later when they attempted to use the air conditioning and all became sick from the mold. They called the technician out again to examine the air vents. They learned the ductwork having been flooded by the storm surge was a cesspool of bacteria and debris. They needed to completely replace the HVAC ductwork in order to have a healthy environment. The estimate for the repairs were reasonable and the new ductwork would be located in the attic instead of under the house.  This would hopefully save it from future floodwaters. Now, if only the insurance company would cooperate, my in-laws could get back to life with a more normal existence.