A massive sinkhole pretty much in the middle of a swamp in Assumption Parish Louisiana has grown to over 370 feet in diameter and is believed to be 400 feet deep. This monster has apparently eaten all the surrounding trees and evacuation was suggested but not mandatory for nearby residents. They believe this opened up as the result of a nearby salt cavern mined by the Texas Brine Company. The cavern was mined for about 30 years until closed and plugged in 2011. Authorities believe the cavern was compromised somehow but there is no evidence currently that they are connected. They have seen bubbling water in the sinkhole raising concerns with some radiation or other contaminants seeping through. The sinkhole even resulted in a natural gas pipeline to bust causing even greater concerns with contaminants or explosions or fires.
Mining was and remains a big industry in Florida as well and we have seen some instances of mining activity activating dormant sinkhole conditions. We also frequently see homes and communities that were built on old mines have serious settlement issues years later once the organic material and fill soils have broken down. This is prominent in the Lakeland region from what we have seen. These homes can experience severe damage and movement in the three to four inch range. Typically when an investigation is done you will see very erratic soils profiles that indicate this is not the normal natural depositional profile of this areas geology. Just because this is occurring however does not necessarily mean sinkhole activity is also not working in concert. The two combined can cause horrible damage.