A boulder the size of a Honda Civic that crashed into a Lanikai home will have to be removed piece by piece.

Meanwhile, the owners of the home, on Ko'oho'o Place in Lanikai, are working to make repairs to the home's foundation, which was pushed in two feet by the boulder, said a relative who asked that his name not be used because the family has asked him not to talk about the incident.

The owners, Ron and Mary Beth Seiple, have lived in their home for 40 years, and have never had a boulder come down the hillside behind their property, the family member said.

The boulder roared down the hill at 4 a.m. Nov. 4, leaving a path of crushed plants and crumbled rock wall terraces behind. Only one of the owners was home at the time, but neighbors said they heard a big clap of thunder, a flash of lightning and then the earth shook as if there was an earthquake.

That night, boulders also fell into a home on 10th Avenue in Palolo and on Hao Street in 'Aina Haina.

The boulder on 10th Avenue rumbled through a bedroom wall and crashed into the bed of a teenager who had just awakened. The Hao Street boulder crashed into a family room where a resident was on a couch watching television.

On Monday, a third boulder fell off a ridge in Hawai'i Kai, crashed into a fence and came within 10 feet of a townhome complex.

Homeowners living in the shadows of steep hillsides are often concerned about rockfalls, landslides and mud flows. After these kind of events, calls come in to state and city offices trying to determine who owns the hillsides, said Deborah Ward, a state Department of Land and Natural Resources spokeswoman.

If the land is among the 1.4 million acres owned by the state, then it will send a geologist out to determine where the boulder came from, Ward said.

"That's more tricky, pinpointing where the boulder came from," Ward said.

Some homeowners are concerned enough about boulders that they're hiring geotechnical firms to scour their land for rockfall and mudslide problems.

In Lanikai, the owners, who are on a trip now, just want to shore up their home, the family member said.

The entire back of the house — a kitchen and dining room — is open to the weather, the sliding glass doors shattered by the boulder. But the main damage was done to the foundation of the home. The boulder bent a hollow tile reinforcing wall, and whenever it rains, water pours into the house.

Yesterday, a plumber was working on adjusting leaky pipes broken by the shift in the foundation in the lower level of the home.

The boulder is believed to have traveled more than 100 yards.

Two smaller boulders, resting above the house, were stopped by a large mango tree.

The property, according to public records, is more than 28,900 square feet

"Luckily, the rock landed where it did," the family member said. "Had it not, it could have come through the house and landed in the house below.

"Nothing like this has ever happened before."

Reach Suzanne Roig at sroig@honoluluadvertiser.com.