Incredible moment Louisiana sinkhole swallows 40ft high trees in a swamp Sinkhole opened up last August after locals noticed gas bubbling on the surface and a strong smell of diesel It is now at least 28 acres, the size of around 21 football fields, and is continuing to grow This is the incredible moment a sinkhole swallows up a large cluster of 40ft high trees in one big gulp. Footage taken in a Louisiana swamp, shows the huge trees leaning slightly before plunging below the surface in a matter of seconds. The sinkhole near Bayou Corne in Assumption Parish first opened up last August after locals noticed gas bubbling on the surface and a strong smell of diesel. Sinkhole: The cluster of tall trees growing out of the Louisianan swamp moments before they are swallowed up It is now at least 28 acres, the size of around 21 football fields, and is continuing to grow. Authorities are currently unsure as to exactly what is causing it but say that no local residents are in danger. One theory is that the sinkhole was created by the mining of underground salt caverns in the area. The land is currently leased to mining company Texas Brine which specialises in injection mining, where freshwater is pumped into the caverns forcing saltwater to the surface. Going: Currents swirl and the trees begin to lean forwards as the sinkhole opens up Going: The trees begin to plunge beneath the surface with only the top branches visible Gone: The trees are now completely submerged. The sinkhole is currently the size of 21 football fields and continues to grow The saltwater is broken down into sodium hydroxide and chlorine which are used in manufacturing industries. Exploratory drilling showed the sinkhole emerged after a cavern's side wall collapse. Texas Brine currently say they have no idea why the cavern suddenly collapsed. However they have reportedly offered compensation deals to those affected many of which have been accepted.