Thane is expected to be closed off from downtown Juneau until late afternoon at the earliest and possibly until Tuesday as state road crews work to clear natural and human-triggered avalanches.
The slides cut off power areawide and telephones in Thane.
A resident told police about 3 a.m. that Thane Road was blocked by an avalanche 100 feet long and 20 feet deep, about 2 miles south of downtown. It's the Cross Bay Creek avalanche path, near Suicide Falls.
The avalanche hadn't been checked for humans or vehicles this morning. But no one was reported missing, said police Sgt. Troy Wilson. The road was closed to pedestrians and vehicles.
The Coast Guard would provide a boat for emergency services, or help could be helicoptered in, Wilson said. ``If things get real bad, we can get services to those folks.''
Juneau residents are looking at flowers in their yards, but at high elevations it's still snowy, said Bill Glude, director of the Southeast Alaska Avalanche Center.
The slide probably was caused by rain and winds lashing a heavy snow pack, Glude said. ``We probably got a little shot of rain at elevation, and everything cut loose.''
That first slide might have taken a few hours to clear. But about 8:30 a.m. a state highway crew started firing howitzer shells across Gastineau Channel from a site above Sandy Beach. They wanted to dislodge any unstable snow before sending in road-clearing crews.
``The best thing we can do is pepper that mountain a whole bunch of times so we can safely work,'' said John Boddy, a Department of Transportation equipment operator on the town side of the slide.
The shells triggered a much bigger avalanche over Thane Road at 8:40 a.m.
The big slide was a chain of sounds, starting with a crack from the howitzer, followed by a booming echo, a whump when the shell hit Mount Roberts, and then a growing rumble as snow rolled several thousand feet down the Snowslide Creek avalanche path, a little south of the GCI earth station.
The slide, which fanned out near the road and dumped itself into the channel, brought with it a cloud of powdery snow that sat over the water like a huge cruise ship until it blew away, leaving a brown-stained mountain.
The slide, which covered about 300 feet of road and was perhaps
50 feet deep, will take at least all day to clear, Boddy said. Roadclearing crews probably won't work at night because they wouldn't be able to see any further slides coming down.
Boddy and Erling Olsen were waiting with one front-end loader this morning. But with the humantriggered slides, the department will hire a couple more loaders and a bulldozer today, Boddy said.
One of the slides broke a line carrying Snettisham power to Juneau's electrical grid. That line hit another line, shutting both down. Alaska Electric Light and Power Co. switched to diesel generators and electricity was restored to all customers by 9:55 a.m.
Spokesman Peter Bibb said he expected one line should be able to carry power later today. Snettisham is a hydroelectric plant southeast of Juneau powered by water from two lakes.
Phones in Thane were also cut off by the slides, but were restored by midday.
Most Thane residents stranded on the south side of the slides were taking it in stride this morning. The Transportation Department helicoptered in a staffer to keep residents informed.
``I called my boss and he wouldn't believe me,'' said Jerry Hughes, 31, a carpenter. ``He thought I might be able to squeeze by. Being Monday, I suppose I have a lot to do today.''
Brendan Carson, 28, a teacher at the Alaska Vocational Institute, said he's often looked up the hill, with his window rolled down, to keep an eye out for slides.
``When you're driving down, you don't know,'' Carson said.
Snow in the Cross Bay Creek path, the site of the first slide, hasn't hit the road for 10 years, said Glude, the avalanche expert.
But in February 1974, it was the path that killed a state crew foreman, Duane Gifford. He was working at night to clear the road from a slide when another slide came down.
The path of the big, howitzertriggered slide is the most frequent slide zone along Thane Road, Glude said. Slides hit the road there about once a year. They have dusted the road about six times this year, and today's slide is the second one to put debris on the road.
Empire reporter Svend Holst contributed to this article.