A Kaua'i couple was shaken but uninjured yesterday morning when several large pieces of lumber fell out of a strapped-together bundle while a helicopter was transporting the building materials to a botanical garden next to their home in Hā'ena.

One of the lumber pieces crashed through the roof of the open-air lānai attached to the back of their home.

"It was a little after 8 (a.m.) when I heard a loud bang — I thought the helicopter had crashed," Nancy Soppeland said.

She was in a bedroom next to the lānai when the lumber crashed.

Soppeland said the helicopter had been ferrying the lumber to the adjacent Limahuli National Tropical Botanical Garden.

She described the lumber as being about 4 inches square and about 4 feet long. In addition to the piece that crashed through the lānai roof, several pieces wound up in the backyard and possibly in the surrounding "jungle."

"It was pretty terrifying, but fortunately no one was hurt," Soppeland said.

She said the couple's dog Winter took off down the beach after the crash and that it took her about two hours to coax the dog close enough to put a collar on.

Her husband, Mark Soppeland, said he had just come into the cottage through the lānai and back door "about 15 seconds before" the incident.

"I was a little bit shaken, but certainly not traumatized by it," he said.

A landscaping contractor who sometimes works on projects in the Botanical Garden, Mark Soppeland said it is not uncommon for helicopters to ferry materials into the more remote areas of the garden.

"I knew they would be flying today even though it was really, really blustery," Soppeland said. "They usually try to avoid flying over our house by going to the east or the west of it."

He said garden employees came to the cottage very quickly after the accident.

"They were kind of shaken by it, too, and I told them, 'Look, accidents happen, it's unfortunate, but they do, but we're all OK,' " Soppeland said.

He said the falling lumber damaged several clear, corrugated roofing panels and some of the lānai's wooden frame.

David Burney, director of conservation for the nonprofit National Tropical Botanical Gardens organization, which operates four gardens on Kaua'i and one in Florida, said the helicopter was carrying a load of plywood and wood posts needed to build a composting toilet when gusty winds caused the cargo bundle to begin spinning.

The pilot decided to gain some altitude and was hoping to duck behind a mountain to get into calmer air to stop the cargo from spinning when centrifugal force caused some of the bundled four-by-fours to come loose and fall to the ground.

He said the pilot wasn't over the house when the lumber came loose but the force that dislodged the wood and the gusty winds carried it toward the cottage.

Burney estimated the damage to the cottage at "a couple of hundred of dollars" and said garden employees were "already on their way to Home Depot" to buy the materials to repair the damaged lānai.

"We're just very thankful that no one was injured," Burney said.