Star-Bulletin file photo
People dropped off flowers at the Sacred Falls sign,
making a makeshift memorial at the park. Police have
strung yellow tape across the entrance to the park,
marking it off limits.

---

Close Sacred Falls,
study says

A federal geological report
recommends the site of the
Mother's Day tragedy be
made permanently off limits

By Jaymes K. Song
Star-Bulletin

A U.S. Geological Survey team is recommending permanent closure of Sacred Falls State Park, deeming the area very dangerous.

The suggestion is cited in a nine-page study for the state, completed by Geological Survey Hazards Team geologists Randall Jibson and Rex Baum of Golden, Colo., following the May 9 rock slide at the falls which killed eight hikers and injured 32 others.

"Whether (another rock fall) will be in the same place or not, we don't know," Baum said yesterday. "There's evidence that rock falls fairly often in that canyon."

The Kaluanui Gulch, in which Sacred Falls is nestled, and neighboring Maakua Gulch are very high-hazard areas for rock falls, geologists said.

Community members have expressed to officials of the state Department of Land and Natural Resources that they want the park to be closed to give it "time to heal."

Family members of the victims have also said they want the park to stay closed.

"I do not want to have it opened," said Darcelle Chan, who lost her sister Donna Kim Chan Forsch in the Mother's Day rock fall.

The park had at least four rock falls causing injury or death at the falls before the May 9 incident.

Victims include a 4-year-old girl killed by a falling rock in 1983, and several hikers trapped under an avalanche in 1970.

Chan said if it is opened, she would be concerned for the safety of the hikers.

The park remains closed indefinitely. According to Land and Natural Resources officials, assessments are still being done, and a decision on whether to reopen the park is expected at the end of the year.

In recent examinations there has been evidence of rock falls into the valley and onto trails, said a department spokeswoman.

The study lists three general ways that rock slides possibly could be minimized:

Removing landslide material or strengthening the slope by using bolts, retaining structures or cement.
Building retaining structures such as nets that would catch falling rocks.
Limiting access to areas near the base of the slopes that are within the range of falling or bouncing rocks.

But the Geological Survey said the three methods are not viable at Sacred Falls for several reasons, among them aesthetic concerns and getting heavy equipment to hazardous areas.

Geological Survey officials said the report is merely a recommendation and information for the state.

The federal agency has no jurisdiction over opening or closing the park.

Geologists determined that the rocks fell from about 480 feet.

The rocks cascaded down a steep, dry waterfall chute for the first 330 feet and were airborne for the last 150 feet.

People had only seconds to react.

The rocks were determined to be falling at 100 to 150 feet per second, or 70 to 100 mph.

But even if everyone knew the rocks were falling, there was little they could have done.

"Due to the confining shape of the canyon, the 60 people who were there at the time had no place to find any protection, because the rock-fall fragments were ricocheting back and forth from one wall to the other," the report said.

"It is remarkable that, out of the 60 people present, there were only eight fatalities and 32 injuries."

The report said the boulders and rocks were less than 2 feet wide, contrary to previous reports that the boulders were the size of cars and refrigerators.

"If boulders are falling out of the sky, they probably look bigger than they are," Baum said.

The report offered no clear explanation why the rocks fell, except that "slope materials gradually weaken over time because of weathering, infiltration of water, root wedging and other physical processes."

The geologists discounted the theory that rocks were loosened by vibrations from sonic booms and low-flying helicopters. They have also discounted the theory of the slope being too dry.

The study concludes by saying a detailed assessment of potential rock-fall areas can be done with ground and aerial investigations.

The study will be released to the public on the Internet next week.

It can be found at http://geohazards.cr.usgs.gov.