JUNEAU (AP) -- A slide triggered by avalanche control efforts knocked out power lines and cut off an outlying section of Juneau from the rest of the city Monday.
The slide, which followed a natural avalanche five hours earlier, fell in a regular avalanche zone and put a second obstacle over the road to Thane, the site of about 80 homes south of downtown Juneau.
The second slide also took down power lines from the Snettisham hydroelectric plant, the capital's regular source of power. Power was restored after about an hour using diesel generators.
Department of Transportation workers used bulldozers and front-end loaders to begin moving debris but planned to quit at nightfall.
''They will stop at dark, and that's due to safety concerns on their part,'' said Juneau Police Sgt. Troy Wilson.
Workers expected to finish clearing the road Tuesday.
Police received a call shortly after 3 a.m. that the Thane Road was blocked by an avalanche about two miles south of downtown Juneau. The first slide was about 100 feet long and 20 feet deep over the road.
As of Monday night, no one had been reported missing in the slide, Wilson said.
Bill Glude, director of the Southeast Alaska Avalanche Center, said rain and winds lashing a heavy snow pack was most likely the cause.
''We probably got a little shot of rain at elevation, and everything cut loose,'' Glude told the Juneau Empire.
At about 8:30 a.m., a state highway crew began firing howitzer shells from Douglas Island across Gastineau Channel to dislodge unstable snow before sending in road-clearing crews.
The shells triggered a much bigger avalanche at 8:40 a.m. The second slide covered about 300 feet of road and was perhaps 50 feet deep.
''It took out a big gouge out of the mountain, lots of rock and mud,'' said Peter Bibb, a spokesman for Alaska Electric Light and Power Co., who saw the avalanche zone from the air.
The city is serviced by two power lines from the Snettisham plant, one on the mountainside and one along the beach. The slide broke the upper line and apparently pushed it into the other, shutting both down.
Bibb said the slide did not damage the towers. A slide in 1989 triggered by DOT wiped out the power lines, which had to be completely replaced, Bibb said.
One line was expected to be back in service late Monday. Bibb said he did not know whether the utility would ask the Department of Transportation to pay for the cost of repairing the line.
DOT spokesman Dennis Poshard said workers can control the timing of the slide but not where it goes.
''It's probably bigger than we wanted, but that's why we do it,'' Poshard said. ''Safety is the first and foremost issue.''
Most Thane residents took the isolation in stride.
''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.''
Glude said snow in the Cross Bay Creek path, the site of the first slide, has not hit the road for 10 years. In February 1974 a state crew foreman, Duane Gifford, was killed while working at night to clear the road from a slide when another came down.
Slides are more frequent in the second zone. Glude said avalanches hit the road there about once per year. The slide Monday was the second to put debris on the road this winter.
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