Greg Regelbrugge was speaking with his brother on the phone an hour before a mudslide hit his Washington neighborhood.

Since then, he’s been trying desperately to contact Leon John Regelbrugge III – who goes by “John” -- but without success.

“If someone can survive it, it’s him,” Greg said of his brother John, who’s been in the Navy for 32 years. “He’s a strong man and committed father. If there’s a way to dig himself out of this, he will.”

Treacherous conditions are thwarting rescue efforts a day after the mudslide killed at least three people and left at least 18 others missing.

“We've got a massive amount of mud out there and debris with a very, very fluid, unstable situation,” one official said during a news briefing on Sunday. “It is far too dangerous to be putting responders in that mud.”

Greg Regelbrugge said he’d come out to the scene of the mudslide hoping to aid in the search for his brother and sister-in-law, but officials said it’s too dangerous.

The conditions are so bad that one search team had to be rescued after getting stuck.

The wave of mud has cut off the town of Oso, Wash., obliterated two neighborhoods and has relatives such as Greg Regelbrugge frantically searching for loved ones.

At one point, Greg Regelbrugge thought his sister-in-law possibly had been located, but it turned out to be a false lead.

Eyewitness Paulo Salcao said it was “just a darkness” when the mudslide hit as he sat in his car. Salcao said he was between 100 -150 feet away from a car he saw being washed away by mud.

“I’m just in shock,” he said. “I’m alive now because of the 10, 20, 30 seconds – because of the green van that was in front of me and I didn’t pass them. I’m here now.”