The accidental death of a decorated Schofield Barracks platoon leader was the second such fatality in less than a year in the same remote Wai'anae Mountains ridge line in the back of Mākaha Valley.

The deaths of Garland English on Jan. 10 and well-known hunter and sportsman Eric Sawchuk on Feb. 1, 2009, serve as a reminder of the treacherous and deceptive nature of Hawai'i's lava cliffs.

Those who know the mountains of Hawai'i in general and West O'ahu in particular say Hawai'i has a different kind of geology that's not conducive to traditional rock climbing and rappelling.

English, 29, fell 400 feet to his death while trying to retrieve camping gear. Sawchuk is believed to have slipped on loose rocks on the steep ridge and fallen to his death while bow-hunting for wild goats.

"What we have mostly is volcanic rock, which is full of holes, and it's all cracked, and it crumbles," said Ralph Valentino, spokesman for the Hawaiian Trail and Mountain Club. "It's not structurally sound."

Trails in Hawai'i are narrower, less-well-marked, not as even and have denser growth than trails on the Mainland, Valentino said. Volcanic rocks and soils make for cracking rocks, pukas on the trail and rapid erosion. Many of the trails have steep drop-offs.

English was an activist and adventurer from Averill Park, N.Y. The Bronze Star recipient had served a tour of duty in Iraq and was stationed at Schofield Barracks.

On Jan. 10, he and a friend returned to a rocky cliff to retrieve camping gear the two had lost days earlier while hiking. Authorities believe English ran out of rope as he was rappelling down to reach the gear, and lost his footing as he tried to climb down the rest of the way.

Sawchuk 41, hosted and produced a one-man cable show, "Hawaiian Sportsman TV." His body was found on a ledge above Kea'au Homestead Road.

Steve Rohrmayr, 66, known to many in the area as "Wai'anae Steve," has hiked up and down the Wai'anae cliffs for years. He said hikers and hunters who leave the trails to pick up lost gear or wild game on the slopes run the risk of having the earth cave in under their feet.

"With these beautiful mountains, you'd think there would be mountain climbers who would be driving pitons into the rocks. But the rock is just so rotten you can't do it.

"A lot of Mainlanders don't realize how rotten our rocks are. And you grab ahold of something or to put your foot on and put some weight on it, and it just breaks away."

Valentino said he recently watched hikers use a large stepping stone to advance across a ridge.

"It was a step down," he said. "And the first five people stepped on the rock that was a little bit bigger than a bowling ball, but sort of squared. And then this woman — who was not as heavy as some of the people in front of her — stepped down on it and the rock just disintegrated and she went tumbling. Stuff like that just happens.

"I don't know that the Wai'anae side is really that much more dangerous, but it is drier slopes and it's generally steeper drop-offs. It's a little bit different terrain. And because of that, it's less forgiving."