CHICAGO (AP) — The National Park Service is investigating
what caused a hole in an Indiana dune that swallowed a 6-year-old boy,
trapping him for more than three hours beneath 11 feet of sand before
rescuers could reach him.
geologists theorize that a long-buried tree trunk decomposed and created
the void — and possibly an air pocket that kept the boy alive — in the
dune known as Mt. Baldy, and hope to use ground-sensing equipment to peer
beneath the surface, said Bruce Rowe, a ranger at the Indiana Dunes
Woessner of Sterling, Ill., was unresponsive when he was found last
Friday, but began breathing en route to a waiting ambulance. He remained
in critical but stable condition Wednesday at Comer Children's Hospital in
Chicago, where doctors said he is expected to make a full neurological
recovery, though he may suffer lingering lung problems from inhaling sand.
point, we still don't know what caused the hole," Rowe said, though the
tree theory seems plausible because the dune moves about 4 to 10 feet a
year and "it's covered a lot of trees."
seen evidence of a hole associated with it," Rowe said.
reached Nathan shortly after one of them inserted a probe into the sand in
an area that looked like the outline of a tree trunk. A tree was not
found, though "quite a bit of bark" was, leading to speculation that the
sand many feet below the surface might have been wet enough to hold the
shape of a long-decayed trunk, Rowe said.
certainly is no conclusion that we can draw at this point," he said.
potential explanation is that sand and debris from a higher elevation
washed out underground and discharged at a lower elevation — a phenomenon
known as "piping" — creating a subterranean cavity, said Sam Panno, senior
geochemist at the Illinois Geological Survey. He said he has heard of
people occasionally falling into such cavities, though many of the
formations are stable or collapse on themselves.
cavities can form quickly, making it difficult to detect them and
impractical to scan for them often with ground-penetrating radar or other
Rowe said a
team of geologists and others will meet Thursday to determine the next
steps in the investigation.
Mt. Baldy will
be closed indefinitely, he said. About two-thirds of the dune already was
roped off to try to keep visitors from trampling native dune grasses and
other vegetation that had been planted to help keep the sand in place,
Rowe said. The dune historically moved about 4 feet southward each year,
but in recent years has moved 10-12 feet, he said.
123-foot-tall Mt. Baldy is the tallest of the dunes at the Indiana Dunes
National Lakeshore, which runs for about 25 miles along the southern shore
of Lake Michigan and attracts families, hikers and birdwatchers.
climbing the dune with an 8-year-old friend and their fathers last Friday
when the friend yelled that Nathan had disappeared. Rescuers used
backhoes, shovels and their hands to reach the boy.
said Nathan could be taken off a ventilator by the end of the week and
released from the hospital within two weeks, but may need another month in
a rehab facility.