Investigators will use some high-tech equipment to try to determine why a sand dune collapsed on a young boy at the Indiana Dunes.
Nathan Woessner, 6, survived four hours under the sand because he was trapped in an air pocket.
Starting next week, ground-penetrating radar may be used to examine the dune.
Some geologists theorize that a buried and decomposed tree trunk created the void Woessner wound up in.
Mount Baldy remains closed to visitors until authorities are confident there is no danger of another collapse.