PORTLAND – One homeowner was lucky to be alive and seven families were evacuated after a southwest Portland home slid 300 feet down a steep hill, crashing into two other homes below it.

Sky 8

A SW Portland home slide 300 feet down a hillside, crashing into two homes below.

Kathy and Dave Hendrickson’s home at 6438 SW Burlingame Place is gone, destroyed after it slid from its perch on Burlingame Place down a hillside into the homes situated below on Terwilliger Boulevard.

 Slideshow: Ground scene | Sky 8 photos | Aftermath damage

 Interactive Map: Slide area, aerial view

The home came off its foundation just before 6 a.m. Wednesday.

Chaos as house slides

Neighbor Greg Sherwood told KGW he and another man helped rescue Kathy Hendrickson, who was alone inside her home when it broke loose.

"It sounded like the garbage was going out, sliding across the street," said Sherwood. "Then I realized it was a lot more than that. I looked out the window -- we live right across the street from them -- and I saw the house, it just started to fall over backwards."

Sherwood and several others called 9-1-1. A person can be heard screaming in the background of one of the calls.

Caller: "My next door neighbor's house just fell down the hill.

Dispatcher: "Your neighbor's house fell down the hill?"

Caller: "It fell down the hill! Kathy, get out of there!... I'm watching her, she's standing on top of the house."

Dispatcher: "How far did it fall?

Caller: "It fell down the hillside, oh, it's still going! Kathy, come on... Kathy!"

 Audio: Listen to 9-1-1 call

Sherwood said he and a neighbor used a ladder to help get Hendrickson off her fallen home.

 More: Woman saved with moments to spare

Two other homes were hit before the sliding house came to a halt. Amazingly, no one was seriously injured in either of those homes.

The slide left a gaping hole in the hillside above Terwilliger Boulevard.

KGW-TV Photo

An exposed sprinkler system pipe at the scene of Wednesday's house slide.

The impact created such a scene that a Portland Fire and Rescue official said it was impossible to tell where one house ended and the others began.

Area remains dangerous for residents

Six other families were required to evacuate their homes after the slide and authorities said the main road through the area would be closed off 'indefinitely' until they could be sure more homes won't slide.

 More: 7 families displaced by house slide

Neighbors in this hilly area of Portland say landslides are nothing new. In 1996, during a particularly wet season, neighbors say that homes started making that eerie “snapping sound,” much like the one heard this week, that signals a pending home slide.

 Map: Google map of slide location

People living here said when they heard the snapping boards and “popping trees” they began evacuating their own homes and gathered together outside.

Residents of the affected homes were clearly shaken and did not wish to be immediately interviewed, but they did wonder aloud where they were going to stay in the short term.

Homeowners also weren't sure yet what, if any, protection they could expect from their insurance

 Insurance: Most Portlanders lack landslide coverage

Slide likely human-caused

Some sort of water system leak most likely caused the house slide, according to a Portland State University geologist.

Because the slide moved in such a specific and linear fashion, P.S.U. head geologist Scott Burns said it appears to be a human-caused landslide.

Burns says the slide could have been a consequence of a leaking water main, sewer pipe or a breech in a two-year-old sprinkler system, over saturating the soil and causing it to give way.

 More: Geologists cite multiple factors causing slide

 Blog: What caused the slide?

Water Bureau spokesperson Sarah Bott says the city was confident this catastrophe wasn't caused by any city-maintained pipes or systems.

“This leak was not caused by a faulty water main or a city water system. We have very sophisticated leak detection. We went up there immediately and detected no leaks," she said.

“The people at the bottom were noticing water running down their driveways the day before. What does that tell me? There's a lot of water coming out someplace on the upper part of the slope -- that is a key fact,” Burns said. 

 More: Geologists map slides

While crews worked to determine how and why the slide happened, the city's water authorities took preventative measures to make sure unstable ground surrounding the slide area didn't damage underground pipes, which could exacerbate the situation.

Officials shut off the water main underneath Burlingame Place because any further soil settlement or movement could cause the 80-year-old main to break under pressure.

“We’re trying to take a pre-emptive measure that this main that’s doing fine right now doesn’t suddenly break or the slide keeps moving … so we don’t end up with a broken main pouring thousands of gallons of water and causing more damage,” Water Bureau Chief Engineer Mike Stuhr said.

The water shut off affected 35 homes in the area for several hours, enough time for engineers to install shut-off valves on each side of the main.

Stuhr wouldn’t speculate on what caused or contributed to this house slide but did say his heart went out to the affected families.

Meanwhile, geo-technicians and insurance agents walked delicately on the debris, continuing their investigations. One geo-technician says it would take extensive research into the history of land use at the location before anyone could determine the cause of the slide.