More mysterious holes discovered under shifting Mount Baldy dune, Indiana [1]

Six new mysterious holes have been discovered in the shifting sands of Mount Baldy since last summer when a big hole swallowed a 6-year old boy who remained buried under 3.3 meters (11 feet) of sediment for several hours until he was rescued.

A year after, scientists still don't have the answers on what causes this holes to form on the southern shore of Lake Michigan, USA.

US National Park Service officially closed the Mount Baldy area due to hazardous conditions and the location remains closed until further notice.

So far, scientists from the Environmental Protection Agency (EPA) and the Indiana University Geological Survey have identified six unstable areas, including 80 by 30 meters (263 by 99 foot) area where most of the collapses have occurred.