The people and the USA military need USGS to REASSESS the stability of the Gulf Coast. Florida knows what sinkholes are all too well. This is not fast-moving storms that cause flash flooding, these are sustained rains that cause saturation of the land. Sand will settle when water starts to recede. Sand can "bridge" leaving unknown caverns below the land. 

It is just time. It has been years now that the coastal areas from Texas to North Carolina have received sustained rains with high winds and flooding. The entire region needs to be reassessed for instability.