Searchers armed with heavy equipment and avalanche beacons waded into an area Friday that was devastated by a massive landslide in British Columbia's Interior, where as many as four people were believed to be buried under a several metres of rock, mud and trees.

The slide struck a day earlier at Johnsons Landing, a tiny hamlet on the shores of Kootenay Lake roughly 70 kilometres northeast of Nelson, severely damaging three homes. Four people, including a father, his two daughters and a German tourist, were unaccounted for and feared to be caught in the debris.

A dog team entered the area briefly on Thursday, but precarious conditions prevented personnel from returning for much of the day Friday.

By mid-afternoon, geotechnicians and landslide experts declared the area safe for searchers, said Central Kootenay Regional District spokesman Bill Macpherson.

Macpherson said emergency responders with heavy equipment reached one of the homes. They were carrying avalanche beacons and transmitters for their own safety.

"In spite of ongoing debris movement and continued slope instability, the search of the landslide at Johnsons Landing has resumed this afternoon," Macpherson said in a news release Friday.

"Spotters are in place at positions around the slide path. Geotechnical experts are doing ongoing monitoring of the slide and surrounding area."

Members of a specialized heavy urban search-and-rescue team from Vancouver were dispatched to the area, as were local search-and-rescue crews and the RCMP.

Macpherson said additional personnel would be deployed if conditions remained safe.

The area was only accessible by air or boat, because the dirt road leading to the remote community was covered by landslide debris up to four metres deep.

Lynn Migdal, whose two daughters and ex-husband were among the missing, was attempting to rally searchers from her Florida home, though she feared help might come too late.

"I need hundreds of people with shovels as soon as possible, if there is any chance that my family is still breathing," she said in an interview with The Canadian Press.

"There are three people buried alive right now, hopefully alive, deep down in one of my houses that got torn apart and twisted on its side. ... Yesterday, I understand, they were waiting for it to settle, but they said as soon as it was sunlight that they would try to start digging my family out."

Migdal identified her relatives as 17-year-old Rachel Webber, 22-year-old Diana Webber and her ex-husband, Valentine Webber.

"There was a phone conversation between one of my daughters and her friend," Migdal said. "My daughter said that they were going to be sitting down to breakfast and that my ex-husband was cooking breakfast. They got off the phone and there was an avalanche."

At least three homes in the tiny hamlet of Johnsons Landing were believed to have been crushed by the landslide.

Sarah Jenkins, Valentine Webber's niece, said the family is from the area and had lived on the house for years. Webber built the family's home and a small cabin on the property himself, she said.

Valentine, who goes by Val, is a sailor who worked on shipping vessels until a shoulder injury a couple of years ago.

Rachel is still in high school, while Diana has been attempting to pursuing a career in Los Angeles as a screenwriter, said Jenkins.

"Somebody should get up there and start looking," she said.

A state of local emergency was declared for the area and an evacuation saw several residents taken to the community of Kaslo, across the lake from the slide.

B.C. Premier Christy Clark issued a statement offering her condolences to the families of the missing and praising the work of search-and-rescue personnel.

"On behalf of all British Columbians, I want to express my deepest sympathy to the families and loved ones of the individuals who are missing as a result of this sudden and tragic natural disaster," Clark said in the statement.

"For a small and close-knit community like Johnsons Landing, (Thursday's) tragedy will have a lasting impact. I want everyone to know they have our government's full support as they recover from this very difficult time."

Retired doctor Roland Procter heard the thunderous noise of the slide at about 11 a.m. Thursday while he was reading on his garden deck.

"It was a prolonged 20 to 30-second rumbling that was unlike any rumbling I've ever heard," he said.

"I realized right away there was only one thing it could be."

Procter was about 500 metres away as the massive torrent of mud gushed down from Gar Creek, sweeping up large trees and snapping them like toothpicks as the muck engulfed half of his tiny village.